[This entry is taken from a chapter of Part II of the open-source textbook Spanish-English Cognates: An Unconventional Introduction to Spanish Linguistics.]
Lat. sĕrvĭtūdō and sĕrvĭtūs
The Late Latin word sĕrvĭtūdō was an abstract noun derived from sĕrvus that meant both ‘slavery’ or ‘servitude’. This word was derived from the root sĕrv‑ of the noun sĕrvus by means of the suffix ‑(ĭ‑)tū‑d‑ĭn‑ that derived abstract third declension nouns out of adjectives which described a state or condition. Note that the initial ‑ĭ‑ of this suffix was a linking vowel and not part of the suffix, so it could be left out if not needed as a linking vowel (the linking vowel was more common in certain periods of the history of Latin than in others). These nouns had an irregular nominative singular ending in ‑(ĭ‑)tū‑d‑ō, and their genitive singular ending was ‑(ĭ)tūdĭnis (with the ‑is inflection) and their accusative singular ending was ‑(ĭ)tūdĭnem (with the ‑em inflection).
English and Spanish have borrowed a number of Latin words that contain this suffix. These loans have come from these words’ nominative singular wordform ending in ‑ĭ‑tūdō, which have resulted in the cognate suffixes Eng. ‑(i)tude ~ Sp. ‑(i)tud, as in Eng. magnitude ~ Sp. magnitud, which come from Lat. magnĭtūdō, derived from the adjective magn‑us/a/um ‘big’. As we can see, Lat. magnĭtūdō was structurally equivalent to Eng. bigness (adjective big + suffix ‑ness). As we will see below, Spanish also has a number of patrimonial (inherited, not borrowed) Latin words that contain this suffix, but their ending is not ‑(i)tud but, rather, ‑(i)dumbre.
Eng. servitude [ˈsɜɹ.vɪt.jud] is a 15th century loan from Fr. servitude, which itself is a loanword from the (written) Late Latin noun sĕrvĭtūdō that we just saw. The meaning of the English word is first and foremost ‘the state of being a slave or completely subject to someone more powerful’ (COED). There is a secondary, archaic legal meaning for this word that refers to ‘the subjection of property to an easement’ (COED).
As we said, Lat. sĕrvĭtūdō was formed in Late Latin and it was not the classical Latin term for ‘slavery’ or ‘servitude’. The classical term was not sĕrvĭtūdō, but rather sĕrvĭtūs, a word also derived from the adjectival root sĕrv‑ whose regular stem was sĕrvĭtūt‑. This noun was formed with the suffix ‑(ĭ‑)tūt‑ that derived collective and abstract nouns from adjectives or nouns. As in the case of the suffix ‑ĭ‑tū‑d‑ĭn‑, this one also had an irregular nominative form ‑tūs, as in sĕrvĭtūs (sĕrv‑ĭ‑tūs), but the regular stem came through in other wordforms such as the accusative ‑ĭ‑tūt‑em, as in sĕrvĭtūtem (sĕrv‑ĭ‑tūt‑em), and genitive ‑ĭ‑tūt‑is, as in sĕrvĭtūtis (sĕrv‑ĭ‑tūt‑is).
Old Spanish borrowed a noun servitud quite early on, with the meaning ‘state or condition of slave/servant’ (DLE), though this word was always rare and has become obsolete in modern Spanish (DCEH). Interestingly, however, Sp. servitud is not a cognate of Eng. servitude, despite their similarity, since Sp. servitud comes from classical Lat. sĕrvĭtūs whereas, as we have seen, Eng. servitude comes from Late Lat. sĕrvĭtūdō. When Old Spanish inherited a Latin word containing the suffix ‑tūt‑ (typically without the linking vowel), this ending is typically attested earliest as ‑tute, ‑tut, or ‑tud, with the latter being the form that has survived in Modern Spanish, cf. patrimonial Sp. virtud ‘virtue’, ultimately from Lat. vĭrtus (acc.: vĭrtūtem), earliest attested as bertut, vertut, and vertud (DCEH). (Lat. virtūs originally meant something like ‘manliness, manhood’, since it was derived from the noun vĭr ‘man, male’. Actually, the fact that the patrimonial ‑e‑ that descends from a short Latin ‑ĭ‑ was changed back to ‑i‑ in the spelling, makes this a semi-learned word, cf. Part I, Chapter 1. This explains why Lat. sĕrvĭtūs was borrowed into Spanish as servitud, with the ending ‑itud and not something else. There are very few words in Spanish that contain this suffix, the main ones being the loanwords juventud ‘youth’, also attested early on as joventud (from Lat. iuventūs iuventūtis; cf. Sp. joven ‘young’, a semi-learned word from Lat. iŭvĕnis that replaced the traditional mozo/a), and senectud ‘old age’, a fancy synonym of vejez (from Lat. sĕnectūs, sĕnectūtis, derived from senex ‘old’, genitive senis, comparative senior, the source of Eng. senior and Sp. señor).
There is a further possible reason for the current form ‑tud of this suffix in Spanish, which is the same form that loans of Latin words that contained the suffix ‑tūdō (in the nominative form) have. The reason is that there could have been a confusion between these two Latin suffixes among medieval writers, since they were similar enough and had the same meaning. This confusion or mixing of the two suffixes persists even today in dictionaries, which often only recognize one suffix ‑tud in Modern Spanish, etymologically, mixing examples from both sources.
Spanish does have a real cognate of Eng. servitude, however, with the same meaning, namely servidumbre. This word has several meanings, the main ones being ‘state or condition of being a slave/servant’ (= Eng. servitude, slavery), ‘slave’s/servant’s work’ (= Eng. servant’s/slave work), and ‘set of people serving at one time or in a house’ (= Eng. (staff of) servants, synonym of criados) (DLE). Sp. servidumbre also has the legal sense that we mentioned earlier for Eng. servitude and curiously, it even had a now obsolete sense as the name of the room in a house where one goes to relieve oneself. Sp. servidumbre can translate the English word slavery, but also the word servitude and even the word serfdom (see above). Spanish does not have different words for classical slavery and other types of bondage, including medieval agricultural bondage, the way English does.
Sp. servidumbre contains the patrimonial reflex ‑idumbre of the Latin suffix ‑ĭ‑tū‑d‑ĭn‑, which in the accusative singular form was ‑ĭ‑tū‑d‑ĭn‑em (with the inflection ‑em). Spanish patrimonial or inherited words, that is those that came into the language by word of mouth transmission from Latin words rather than being borrowed much later from written Latin, underwent sound changes that were different from the changes of adaptation that Latin words that were borrowed later on—the learned words or cultismos—underwent (cf. Part I, Chapters 8 and 10). In patrimonial Latin, words that had the ending ‑(ĭ)‑tū‑d‑ĭn‑em, this ending changed to ‑(e/i)dumbre by the time they became Old Spanish words by a series of complicated changes that involved elision, metathesis, epenthesis, and mutation of sounds (cf. Part I, Chapter 10).
servedumbre / servidumbre
Note that servedumbre, with an e, is attested in medieval texts, which makes more sense etymologically, since Latin short ĭ typically changed to Old Sp. e. Also note that in the 13th century, servidumbre is attested as servidumne (Berceo, DCEH). In general, this suffix was often first attested as ‑dumne, not ‑dumbre, in the earliest written texts.
A similar ‑umbre ending (without the ‑(i)d‑ part) is found in patrimonial Spanish words that descend from Vulgar Latin words that ended in ‑mine, such as nombre, from Vulgar Latin nomine, which is an adaptation of classical Lat. nōmen (accusative: nōmen, genitive: nōminis), and legumbre ‘legume’ from Vulgar Latin legumine, an adaptation of Lat. legūmen (acc. legūmen, gen. legūminis). The English words name and legume are cognates of these words, although name is a native (Germanic) English word and legume is a 17th century loanword from Latin that came through French légume, which is itself a 16th century loanword from written Latin (Fr. légume is attested in the 14th century as lesgum).
There aren’t many words that contain the ‑dumbre ending in Modern Spanish. Besides servidumbre, other common ones are the following (note that the first one lacks the characteristic ‑d‑, which was lost somewhere along the way):
- · costumbre ‘custom’, from Lat. cōnsuētūdĭnem (nom. cōnsuētūdō) ‘habituation; custom, etc.’; cognate of It. and Port. costume, Old Fr. coustume, Eng. custom and costume
- · mansedumbre ‘meekness; tameness’, Lat. mānsuētūdĭnem (nom.: mānsuētūdō) ‘tameness, ec.’, cf. Sp. manso/a ‘meek, tame’ < Vulgar Latin *mansus < Latin mānsuētus ‘having been tamed’, passive participle of mānsuēscĕre ‘to tame’
- · muchedumbre ‘crowd, mob’, from Lat. multitūdĭnem ‘numerousness; a great number; a crowd’, from multus ‘much, many’, source of mucho ‘much’; cf. the learned synonym multitud ‘crowd; multitude’
- · certidumbre ‘certainty’, from Lat. certitūdĭnem, from certus ‘certain, sure’, source of Sp. cierto ‘true; certain’; cf. the learned synonym certitud (another synonym: certeza); more common than certidumbre in Spanish is its antonym incertidumbre ‘uncertainty’
There were a few more such words in Old Spanish that are now obsolete, such as soledumbre ‘solitude’, from Lat. sōlitūdĭnem (nom.: sōlitūdō), cf. Modern Sp. soledad, from Lat. sōlĭtātem, accusative wordform of sōlĭtās ‘a being alone, loneliness, solitude’, a synonym of sōlitūdō, both of them derived from the adjective sōlus/a ‘alone, solitary, etc.’, source of Sp. solo/a ‘alone, lonely, etc.’. Some nouns in ‑dumbre were formed in Spanish by analogy with existing inherited ones, e.g.
- podredumbre ‘rottenness, rot, putrefaction’, from pudrir ‘to rot’, earlier also podrir and even more common podrecer, both now obsolete; cf. modern Spanish infinitive pudrir, participle podrido ‘rotten’ (DCEH)
- pesadumbre ‘grief, sorrow’, from the noun pesar ‘sorrow, grief, regret, remorse’, from the verb pesar ‘to weigh’; attested in the 13th century (Berceo, cf. DCEH)
 The original has: ‘servitud Del lat. servĭtus, -ūtis. 1, f. desus. Estado o condición del siervo’ (DLE). The DLE mentions a second sense, which is now also obsolete: ‘2. f. desus. Trabajo propio de un siervo.’ (DLE).
 María Moliner’s dictionary, for example, has: ‘-tud (var. «-itud») Sufijo de nombres de cualidad, actitud o estado: [e.g.] juventud, beatitud, laxitud’ (MM). Note that whereas juventud comes from Lat. iuventūs, beatitud is a loanword from Lat. beatitūdo.
 The original has: ‘servidumbre Del lat. tardío servitūdo, -ĭnis. 1. f. Estado o condición de siervo. 2. f. Trabajo o ejercicio propio del siervo. 3. f. Conjunto de personas que trabajaba en el servicio doméstico de una casa. [in the previous edition of the dictionary: Conjunto de criados que sirven a un tiempo o en una casa] 4. f. Sujeción grave u obligación inexcusable de hacer algo. 5. f. Sujeción causada por las pasiones o afectos que coarta la libertad. 6. f. Der. Derecho en predio ajeno que limita el dominio en este y que está constituido en favor de las necesidades de otra finca perteneciente a distinto propietario, o de quien no es dueño de la gravada. 7. f. desus. retrete (‖ aposento)’ (DLE)