[This entry is taken from a chapter of Part II of the open-source textbook Spanish-English Cognates: An Unconventional Introduction to Spanish Linguistics.]
Eng. enslave and Sp. esclavizar
English converted the noun slave into a verb, to slave, a verb that is attested since the middle of the 16th century. Originally it had the meaning ‘to enslave’, that is, ‘to trade in or transport slaves’ (AHD), but since the early 18th century, the main meaning of this verb has been ‘to work like a slave’ (‘to work very hard’) but only as part of a phrasal verb with the adverbials away or over, cf. slave away (at something), as in I’ve been slaving away at this report, or slave over, as in He’s been slaving over his history essay (LDCE). Spanish translates this expression by different verbs, such as trabajar duro, afanarse, esforzarse, or bregar (UG). The verb to slave was derived in English from the noun slave by conversion, that is, without the addition of affixes (cf. Part I, Chapter 5). In this section, we are going to look at two verbs derived from the words Eng. slave ~ Sp. esclavo that do make use of affixes.
In the mid-17th century English formed another verb for the meaning ‘to trade in or transport slaves’ by means of the prefix en‑, namely enslave, pronounced [ɪn.ˈsleɪ̯v] or [ɛn.ˈsleɪ̯v], depending on the dialect (cf. Part I, Chapter 5, about the prefix en‑ in Spanish and French that descends from the Latin prefix in‑ and which English borrowed through French). This verb means literally ‘to make (someone) a slave’ (MWALD) and it is typically used in the passive voice, as to be enslaved. Also, it is often used figuratively, with the sense ‘cause to lose freedom of choice or action’ (COED), as in She seemed enslaved by hatred (LDCE).
From the past participle enslaved of this verb, English has derived the identical adjective by conversion, as in the phrase enslaved people. Also derived from this verb are the nouns enslavement and enslaver. Eng. enslavement [ɪn.ˈsleɪ̯v.mənt] or [ɛn.ˈsleɪ̯v.mənt], meaning ‘the act or result of enslaving’, was formed in English in the late 17th century from the verb enslave by means of the Latinate suffix ‑ment. Note that to express the meaning ‘the act of enslaving’, English can also use the noun enslaving derived from the verb’s participle formed with the native suffix ‑ing, since such participles can typically be used as nouns in English (as in Flying is dangerous). The less common noun enslaver was formed in the 18th century in English by means of the agent suffix ‑er (the equivalent word in Spanish is esclavista).
The equivalent verb to Eng. enslave in Spanish is esclavizar. It was formed, in Spanish, from the stem esclav‑ of esclavo and the suffix ‑izar that creates transitive verbs, cognate with Eng. ‑ize (cf. Part I, Chapter 5). As with Eng. enslave, Spanish has converted its past participle into an adjective, namely esclavizado/a ‘enslaved’, as in Está esclavizado por el trabajo ‘He’s a slave to his work’ (OSD, ≈ ‘He’s enslaved by/to his work’). Eng. enslave and Sp. esclavizar are, of course, not cognates since they do not descend from the same source, but rather paronyms that share a root and a meaning (see above).
Spanish does not really have a noun derived from the verb esclavizar to refer to ‘the act or result of enslaving’ the way English has enslavement and enslaving. The word esclavizamiento or esclavizaje can been formed in Spanish from the verb, and there are signs that they have been occasionally used, but they never became respectable enough to appear in dictionaries. To express this meaning, Spanish typically uses the same word that means ‘slavery’, namely esclavitud, as we will see in the next section.
 There are almost 10,800 results in a Google search for “esclavizamiento” and 746 for “esclavizaje”.