denude v.

active word-forming element in English and in many verbs inherited from French and Latin, from Latin de "down, down from, from, off; concerning" (see de), also used as a prefix in Latin, usually meaning "down, off, away, from among, down from," but also "down to the bottom, totally" hence "completely" (intensive or completive), which is its sense in many English words.

As a Latin prefix it also had the function of undoing or reversing a verb's action, and hence it came to be used as a pure privative — "not, do the opposite of, undo" — which is its primary function as a living prefix in English, as in defrost (1895), defuse (1943), de-escalate (1964), etc. In some cases, a reduced form of dis-.

Old English nacod "nude, unclothed, bare; empty," also "not fully clothed" (a sense still used in 18c.),  from Proto-Germanic *nakwadaz (source also of Old Frisian nakad, Middle Dutch naket, Dutch naakt, Old High German nackot, German nackt, Old Norse nökkviðr, Old Swedish nakuþer, Gothic naqaþs "naked"), from PIE root *nogw- "naked" (source also of Sanskrit nagna, Hittite nekumant-, Old Persian *nagna-, Greek gymnos, Latin nudus, Lithuanian nuogas, Old Church Slavonic nagu-, Russian nagoi, Old Irish nocht, Welsh noeth "bare, naked").

Of things, "without the usual or customary covering" (of a sword, etc.), from Old English. Applied to qualities, actions, etc., "mere, pure, open to view, unconcealed," from c. 1200; phrase the naked truth is from early 15c. Phrase naked as a jaybird (1943) was earlier naked as a robin (1879, in a Shropshire context); Middle English had naked as a worm (mid-14c.), naked as a needle (late 14c.). Naked eye "the eye unassisted by any instrument" is from 1660s, an unnecessary term before telescopes and microscopes.