There are a number of words derived from the root sĕd‑ of the verb sĕdēre, most of them from the normal-grade variant of the Proto-Indo-European root, though a couple are from other variants, as we shall see. The ones that we are going to look at in this section come from unprefixed forms of this root. A fair number of these words are derived from the passive participle stem sess‑ of the Latin verb sĕdēre, which as we have seen, is the result of an early Latin sound change in which sĕd‑ plus ‑t‑ changed to sess‑.
As we have already seen, the Spanish verb sentar descends from a Vulgar Latin variant of this verb derived from its present active participle of the verb, namely sĕdēns, meaning ‘seating, being seated’. The genitive form of this third-declension participle was sĕdĕntis and, thus, its regular stem was sĕdĕnt‑ (sĕd‑ĕnt‑). From this participle, the first conjugation verb *sĕdĕntāre was derived in Vulgar Latin (sĕd‑ĕnt‑āre), and from it we get the verb sentar in Spanish (sent-ar).
The stem sĕd‑ĕnt‑ of the present participle of the verb sĕdēre is found in a couple more Spanish words, both of them learned, not patrimonial. The first one is the participle itself, which Spanish borrowed as the adjective sedente, which means ‘seated, sitting’. The term was borrowed, as usual, from the accusative form sĕdĕntem of the participle, with the usual adjustment of the inflectional ending by removal of the final ‑m, which is the same sort of change that had affected patrimonial words (cf. Part I, Chapter 10, §10.2). The word sedente is quite fancy, not a regular word. It is used to refer to images, such as sculptures, of people sitting down, as in Virgen sedente ‘sitting Virgin’ or posición sedente ‘sitting position’. This word has no cognate in English.
The other word that contains the root sĕdĕnt‑ in Spanish is not fancy and it does have an English cognate. It is formed by the addition of the first-and-second declension adjective suffix ‑ārĭ‑, from which we get the Latin adjective sĕdĕntārĭus (sĕd‑ĕnt‑ār‑ĭ‑us; fem. sĕdĕntārĭa), that meant ‘sitting, remaining in one place’. This word is the source of the cognates Eng. sedentary ~ Sp. sedentario/a, whose main meanings are ‘characterized by or requiring much sitting’, as in sedentary job, and ‘accustomed to sitting or to taking little exercise’, as in sedentary person (AHD). This was a very rare word in Latin, but it was recovered in French in the late 15th century, though there is an isolated attestation in French in the 11th century. From there, it made its way to English, where it is first attested in the late 16th century, and to Spanish (cf. Mod.Fr. sédentaire [se.dɑ̃.ˈtɛʀ]).
From the stem of the passive participle sess‑ a number of words were derived in Latin, some of which have reached us. One was the adjective sessĭlis, which meant ‘suitable as a seat’ and, when speaking of plants, ‘low-growing, dwarf’. It was formed with the third declension adjective-forming suffix ‑ĭl‑ (sess‑ĭl‑is), the source of Eng. ‑ile in adjectives such as agile and fragile (cf. Sp. ágil and frágil). This adjective was borrowed into Spanish as sésil and into English as sessile (mid-18th century) as a scientific term. In botany, it means ‘stalkless and attached directly at the base’, as in sessile leaves, and in zoology, it means ‘permanently attached or fixed; not free-moving’ and in sessile barnacle.
Besides the verb sĕdēre, there was a noun that contained the same root, without any affixes, namely the Latin noun sēdēs, which meant ‘seat, chair’, as well as ‘place, residence, settlement’ (genitive sēdis, accusative sēdem, root sēd‑). The source of this word was the lengthened e-grade Proto-Indo-European root sēd‑. It seems that in Vulgar Latin, the long ē changed to short ĕ, giving us *sĕdem in the accusative. The reason for thinking this is that the patrimonial version of this word in Old French was sié or sied. Later, however, the word was readjusted’ to make it more like the original, and it is attested as sé or sed. That is when the word was borrowed by English as see around the year 1300 with the meaning ‘throne of a bishop, archbishop, or pope’. This Eng. see (a homonym of the verb see) is a rare word today that refers to ‘the official seat, center of authority, jurisdiction, or office of a bishop’ (AHD), but it is only used regularly in the phrase Holy See, i.e. the see of the Catholic pope in Rome. (Old French se/sed, the source of Eng. see, has been replaced in Modern French by siège, as in (le) Saint-Siège, see below.)
The reflex of Lat. sēdēs in Spanish is sede, which is a 16th century loanword from Latin. The equivalent of Holy See in Spanish is Santa Sede. Spanish sede has additional religious uses, such as to refer to a diocese or the capital of a diocese. (A diocesis [ˈdaɪ̯.ə.sɪs], Sp. diócesis, is ‘a district under the pastoral care of a bishop in the Christian Church’, COED.) However, Sp. sede has additional, non-religious meanings, namely ‘headquarters, central office (of an organization)’, ‘seat (of government)’, or ‘venue’ (of a congress, fair, or event), e.g. la sede del partido ‘party headquarters’ or la sede de las Naciones Unidas ‘the head office of the United Nations’, la sede de los Juegos Olímpicos de 1984 ‘the venue or host of the 1984 Olympic Games’.
Another rare, Church-related word derived from the same root is Eng. sedile ~ Sp. sedil. The meaning of these words is ‘one of a set of seats, usually three, provided in some Roman Catholic and Anglican churches for the use of the presiding clergy, traditionally placed on the epistle side of the choir near the altar, and in Gothic-style churches often built into the wall’ (AHD). The word comes from Lat. (nominative and accusative) sĕdīle (gen. sĕdĭlis), a third declension neuter pure i-stem noun that meant ‘seat, bench, stool, chair’, which was used mostly in poetry. Eng. sedile is pronounced [sɪ.ˈdaɪ̯.li] and its plural is sedilia [sɪ.ˈdɪ.lɪ.ə].
Latin had a less poetic synonym of sĕdīle for the meaning ‘seat, chair, stool’, namely sella (gen. sellae, acc. sellam). This word has been reconstructed as coming from Proto-Italic *sedlā, a word derived from the Proto-Indo-European root sed‑. The patrimonial descendant of this word in Spanish is silla ‘chair’ (cf. Cat. sella, It. sella, Occ. sèla, Fr. selle, Port. sela, Sicilian sedda). The raising of the e vowel to i is the result of the yod-effect of the adjacent palatal sound [ʎ], written 〈ll〉, derived from Lat. [ll] (cf. Part I, Chapter 10, §10.3.6 and §10.4.4.4). The word is first attested in the 10th century as siella, with the expected diphthong ie coming from a stressed Latin short ĕ. By the way, Sp. silla has a distant relative or even cognate in Spanish, namely Eng. saddle (Sp. silla de montar). That is because Lat. sella has been reconstructed as coming come from Proto-Italic source has been reconstructed as *sedlā, which is akin to the source of Eng. saddle, namely Proto-Germanic *sadulaz, which is thought to come from the Proto-Indo-European stem *sod‑tló- or *sod‑dʰlo‑, a derived form of the o-grade variant of the root sed‑.
Vulgar Latin had yet another word for ‘seat’, namely *sĕdĭcum (sĕd‑ĭc‑um), derived most likely from an unattested verb *sedicare (not from the noun sēdēs ‘seat’). This noun, which never made it into Spanish, became Old French sege, siege, or seige ‘seat’, which is siège [ˈsjɛʒ] in Modern French, meaning ‘seat’ but also ‘headquarters’ (cf. Sp. sede), ‘see’ (cf. Sp. sede), and ‘siege’ (cf. Sp. sitio below).
Besides meaning ‘seat’, the Vulgar Latin word *sĕdĭcum had an additional, military meaning, namely ‘siege, besieging’, presumably because a siege involves a lot of sitting before a (besieged) fortress. English borrowed the word siege [ˈsiʤ] from Old French with just its current meaning, namely ‘a military operation in which enemy forces surround a town or building, cutting off essential supplies, with the aim of compelling the surrender of those inside’ (COED). This word is first attested in English in the early 13th century.
Derived from the noun siege, English has the verb to besiege, derived from the Old English prefix be‑ around the year 1300. It is equivalent to the expression to lay siege and it means to ‘surround (a place) with armed forces in order to capture it or force its surrender’ (COED). The verb besiege is probably a calque of Old French assiege or asegier, with the same meaning (Mod. Fr. assiéger; for calques, see Part I, Chapter 4, §4.8.2). This word assiege was indeed borrowed into English, giving us the archaic assiege, which is a synonym of besiege. This French verb comes from a Vulgar Latin *assedicare related to the Vulgar Latin word for ‘seat’ that we just saw, namely *sĕdĭcum (ad‑sĕd‑ĭc‑ā-re). We return to this verb below.
Old English had a different word for the meaning ‘besiege’, namely besittan, derived from sittan (the source of Eng. sit) and the prefix be‑. Its source is Proto-Germanic *bisitjaną ‘to sit near, sit among or around’. The prefix be‑, from Proto-Germanic *bi‑, and cognate with the English preposition by, was a productive one in the Germanic family of languages, with a wide range of meanings. It formed verbs and adjectives, but especially transitive verbs with the sense ‘around, on all sides, throughout, etc.’. All this seems to indicate that Eng. besiege is a blend of native (patrimonial) Old English besittan and Old French siege and/or assiege, both of which contain the same Indo-European root.
It is quite interesting that the words for siege in besiege in Spanish also seem to be a mixture of Germanic and Latinate words which also contain the same Indo-European root. Spanish has two words that translate Eng. siege, namely asedio and sitio. Likewise, the verb to besiege translates as either asediar or sitiar. In the noun asedio and the verb asediar, we recognize the root sed‑. The matter of the noun sitio and the verb sitiar is a bit more complicated, as we shall see.
Let us start with the word sitio, a word that most commonly means ‘place’ in Modern Spanish, synonymous with lugar, but which also means ‘siege’, a meaning that is associated with the verb sitiar ‘to besiege, lay siege’. The word sitio is first attested, in the 14th century, as sito, which would seem to imply that it is a learned borrowing from Lat. sĭtus that meant, among other things, ‘the manner of lying, the situation, local position, site of a thing’ (L&S). This word is also the source of Eng. site [ˈsaɪ̯t], ‘an area of ground on which something is located’, ‘a place where a particular event or activity is occurring or has occurred’ (COED). Nowadays, site is also often short for website or Web site.
The only problem with the word sitio is the second ‑i‑, which is an unexpected addition to this word. It has been explained as an analogy with the related verb sitiar which now in Spanish can only mean ‘to besiege, lay siege’, which has an i in the same position. The origin of this verb is not totally clear. Some think that it comes from the Medieval Latin verb sĭtŭāre ‘to place, situate, locate’, derived from Lat sĭtus, the source of learned Eng. situate ~ Sp. situar (sĭt‑ŭ‑āre; notice the uncommon transfer of the ‑ŭ‑ from the inflection of sĭtus to the stem of sĭtŭāre). But the ‑u‑ of the Latin verb does not match the ‑i‑ of the Spanish verb sitiar, a most uncommon change.
More appealing perhaps is the possibility that sitiar is related to the Germanic (Gothic) verb sittjan, cognate of Old English sittan, the source of Eng. sit (see above), and unrelated to Lat. sĭtŭāre. This would explain the ‑i‑, which would have then been transferred to the noun sitio by analogy. In other words, the origin of sitiar may well be Germanic and, thus, there are two words sitio in Spanish, one meaning ‘siege’ that derives from the verb sitiar, and one that is a loanword from Lat. sĭtus, which was originally sito, but which eventually changed to sitio under the influence of the first sitio. It is very likely that all this came about by an understandable confusion between these words.
Let us look now at the other Spanish words for ‘siege’ and ‘besiege’, namely asedio and asediar. The verb is said to be derived from the noun and the noun seems to descend from Lat. obsĭdĭum, a word meaning ‘a siege, investment, blockade’ (ob‑sĭd‑ĭ‑um; a synonym of in Latin was or obsĭdĭō, acc. obsidiōnem). This noun is derived from the verb obsĭdēre ‘to sit, remain, abide, stay’, derived from sĕdēre ‘to sit, be seated’ (ob‑sĭd‑ē‑re). (The ‑i‑ in asedio is another possible analogical source of the ‑i‑ in sitio and sitiar, another complication to the explanation of the origin of these words.) The verb asediar could not have come from the verb obsĭdēre, so it must have been derived, in Spanish, from the noun asedio. This would explain the ‑i‑ in asediar as well as the fact that it is a first conjugation verb.
There is problem, however, with deriving Sp. asedio from Lat. obsĭdĭum. The change of Latin short ĭ to e is as expected in a patrimonial word. The loss of the syllable-final ‑b‑ is also to be expected. The change of the initial vowel from o‑ to a‑ is quite unexpected, however. If we add to that the fact that the French word for ‘siege’, assiege (from Vulgar Latin *assedicare), starts with a‑, although the word comes from a different source, this suggests that more is going on here. Also, in a patrimonial word, we would not have expected the ‑di‑ sound combination to have been maintained, unless it was a semi-learned reconstruction of the word. One possibility is that asedio could be a semi-learned blend of Lat. obsĭdĭum and Vulgar Latin *assedicare (or Old French assiege).
The cognates Eng. sediment ~ Sp. sedimento are loanwords from the Latin word sĕdĭmentum, which meant ‘a settling, sinking down, subsidence’ (sĕd‑ĭ‑ment‑um). English borrowed this word in the mid-16th century, probably through learned French sédiment, and the Spanish word obviously has the same source (sedimento first appears in the DRAE in the 19th century). That is why all of these words have the same meaning today, namely ‘matter that settles to the bottom of a liquid’ (COED).
Lat. sĕdĭmentum is formed with the second declension derivational suffix ‑ment‑(um), meaning primarily ‘instrument, medium, or result’ (cf. Part I, Chapter 8, §18.104.22.168). The word sediment is first attested in English in the mid-16th century and it seems to have been borrowed it from Middle French sediment, which borrowed the word from Latin at around the same time. Since Sp. sedimento is not attested until much later, this word must also have been a loanword from the French word.
Latin derived nouns (typically abstract nouns) from verbs by means of the suffix ‑ĭōn‑ (‑ĭo in the nominative case), which attached itself to the supine (passive participle) stem of verbs (cf. Part I, Chapter 10). When this suffix was attached to the supine stem sess‑ of the verb sĕdēre, it resulted in the noun sĕssĭo ‘act of sitting’, ‘a sitting (down), session’ (genitive sĕssĭōnis, accusative sĕssĭōnem). This noun is the source of the cognates Eng. session [ˈsɛ.ʃən] ~ Sp. sesión [se.ˈsi̯on]. English borrowed this word through Old French session in the late 14th century. Sp. sesión is not attested until the 17th century and it must have come through French as well. The main meaning of these good friends is ‘a period of time used for a particular activity, especially by a group of people’ (DOCE).
The cognates Eng. sedan ~ Sp. sedán are also thought to derive from the Latin root sĕd‑, though the actual source of these words is not clear. It is possible that its source is a southern Italian dialect. The English word sedan today means ‘a closed automobile having two or four doors and a front and rear seat’ (AHD), a word used primarily used in North American English (a synonym is saloon car). The traditional meaning of this word, which was short for sedan chair, was ‘an enclosed chair for conveying one person, carried between horizontal poles by two porters, common in the 17th and 18th centuries’ (COED). The Spanish equivalent was silla de manos or palanquín. The Spanish word sedán is a loanword from Eng. sedan, with the modern meaning of ‘automobile’. This word is only used in some dialects of Spanish. This type of car is perhaps more commonly known in Spanish turismo (short for coche de turismo) or berlina.
There are two English words that go back to words with the Latin root sed‑, although they do not have Spanish cognates. One is seance, also spelled séance [ˈseɪ̯.ɒns], a late 18th century loanword from French séance. Eng. séance means ‘a meeting at which people attempt to make contact with the dead’ (COED). In French, the noun seance meant ‘a sitting (period)’, and it is derived from the verb seoir [swaʀ] ‘to sit’, which comes from Lat. sĕdēre (Old French seeir) which in Modern French is only used in the past participle form, sis ‘located/situated’ (cf. sis à ‘located at’). (In earlier French, it was used also in the infinitive and the imperative.) The equivalent Spanish term for Eng. séance is sesión de espiritismo.
The other English word that derives from a word that contained the root sed‑ is quite an unlikely one, namely the noun size [ˈsaɪ̯z]. This word was borrowed around the year 1300 from Old French sise with the meaning ‘ordinance to fix the amount of a payment or tax’, a meaning that is now obsolete. This French word was a shortened version of the word assise, which had several meanings: ‘session’, ‘assessment’, ‘regulation’, ‘manner’. The version sise is probably the result of mis-dividing the phrase l’assise as la sise. The sense ‘extent, amount, volume, magnitude’ of Eng. size is first attested around the year 1300 and it is derived from the regulating sense, out of the idea of fixing measures of things such as weights or portions. Eng. size typically translates into Spanish as tamaño or, in some cases, magnitud. When speaking of clothes’ size, it translates as talla and when speaking of shoe or glove size, it translates as número (cf. número de zapato, número de guante).
We should mention that from the feminine form of the past participle of the verb sentar, sentado/a, Spanish has derived by conversion (zero-derivation) the noun sentada. Its original meaning was ‘period time in which a person remains seated without interruption’, as in Leyó el libro de una sentada ‘She read the book in one sitting’. One can imagine that this was not a very common word until in the late 20th century it came to refer to ‘a form of protest in which demonstrators occupy a place until their demands are met’ or what in English is called a sit-in. (For more on conversion, see Part I, Chapter 5, §5.7.)
Finally, to avoid confusion, we should mention that there was an unrelated Old Latin morpheme that looks like our sĕd‑, namely the Old Latin preposition and adverb sēd ‘without, apart’, which when used as a conjunction meant ‘but’. In Classical Latin times, this morpheme had changed to sē, though it is still found as sed‑ in one word, namely sēditio ‘sedition’, lit. ‘going apart’. In one adjective, it is found as sē‑, namely sēcūrus ‘secure’, from the phrase sē cūrā ‘without care’. The same sē is also found in a number of verbs as a prefix, such as sēcēdĕre, sēclūdĕre, sēdūcĕre, sēgregāre, and sēparāre (OED), cf. Eng. secede, seclude, seduce, segregate, and separate.
 The third declension Latin suffix ‑īl‑ found in this word (‑īl‑e ‑īl‑is) is a rare one, used mostly to create names of enclosures for animals, e.g. agnīle ‘sheepfold’, from agnus ‘lamb’, ovīle ‘sheepfold’, from ovis ‘sheep’ (cf. also bovīle, caprīle, equīle, porcīle, and suīle). The word sedīle must be a very old derivation.
 It was common for ie to change to i before palatal [ʎ] in Old Spanish, e.g. castellum ‘castle, fort, citadel, stronghold; fortified village’ > O.Sp. castiello > Sp. castillo ‘castle’. (Eng. castle [ˈkæ.səɫ] entered the language both through Norman French and through Latin, at different times, eventually merging into a single word. Lat. castellum was a diminutive of castrum ‘castle, fort’ (pl. castra ‘(military) camp’), which may have been derived from Lat. casa. Lat. castrum is the source of Eng. chester and caster, now only found in place names such as Manchester and Lancaster.)
 There are two words sĭtus in Latin. One is the passive participle of the verb sinĕre ‘to let, permit; to put, lay, set down’. The verb pōnĕre, source of Sp. poner ‘to put’, is derived from the verb sinĕre with the prefix po‑ ‘off, away’, which explains this verb’s passive participle pŏsĭtus, source of Sp. puesto. Spanish has a fance adjective sito derived from this Latin sĭtus, which is used as an adjective, synonymous with situado and ubicado, all meaning ‘located’ in English.
The other word sĭtus is the one we’re interested in here. In addition to the meaning ‘a place, position, situation, location, station’, it also had other quite unrelated meanings, namely, ‘idleness, sloth, inactivity’, ‘forgetfulness’, and ‘the effects of neglect’, which have not survived in this word’s descendants.
 Another example of this transfer of an inflectional vowel to a derived word is in the word manual, from Late Latin manuāle ‘handbook, manual’, derived from Lat. manus ‘hand’.
 Lat. sĕdĭmentum was a synonym of another Latin word, namely sĕdĭmen (genitive: sĕdĭmĭnis, regular stem sĕdĭmĭn‑) ‘settlings, sediment’. Other examples of such doublets are fragmen-fragmentum, documen-documentum. English borrowed the word sedimen from Latin in the 17th century with the same meaning as sedimentum, but that word is now obsolete.
 In Modern French, assisse is just the past participle of the verb asseoir [aswar] ‘to seat’, equivalent Sp. sentar; and cousin of reflexive s’asseoir ‘to sit (down)’, equivalent of Sp. sentarse.
 Sp. tamaño is derived from the phrase tam magnus ‘so big’. Sp. magnitud, just like Eng. magnitude, comes from Lat. magnitūdō ‘greatness, size, etc.’, derived from the adjective magnus ‘big, great’ and the ending ‑tūdō used to derive from adjectives abstract nouns that indicate a state or condition (the genitive form of the suffix was ‑tūdinis and the regular morpheme ‑tūdin‑.
 The Spanish preposition sin ‘without’ comes from Lat. sĭne ‘without’, which was a replacement in Classical Latin of the Old Latin preposition sē/sēd. In the final analysis, it was presumably a combination of sē and nē ‘not’. This sē is related to the Spanish reflexive pronoun se, since they both come ultimately from Proto-Indo-European *swé ‘self’ (cf. the meaning ‘by itself’ became ‘without’). By the way, the patrimonial English word self also goes back ultimately to the same Proto-Indo-European *swé, since it has been reconstructed as an extended suffixed form of it, namely PIE *sel‑bho‑. The i in Sp. sin is a bit of a mystery. Since it came from sĭne, it should be been sen. The variant sen as well as the variant sien are found in Medieval Spanish. The most likely thing is that it is a semi-learned repair job.