nudity n.

1530s, a legal term, "unsupported, not formally attested," from Latin nudus "naked, bare, unclothed, stripped," from PIE root *nogw- "naked" (see naked). General sense of "mere, plain, simple" is attested from 1550s. In reference to the human body, "unclothed, undraped," it is an artistic euphemism for naked, dating from 1610s (implied in nudity) but not in common use in this sense until mid-19c.

word-forming element making abstract nouns from adjectives and meaning "condition or quality of being ______," from Middle English -ite, from Old French -ete (Modern French -ité) and directly from Latin -itatem (nominative -itas), suffix denoting state or condition, composed of -i- (from the stem or else a connective) + the common abstract suffix -tas (see -ty (2)).

Roughly, the word in -ity usually means the quality of being what the adjective describes, or concretely an instance of the quality, or collectively all the instances; & the word in -ism means the disposition, or collectively all those who feel it. [Fowler]

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.