"worrisome or suspenseful experience," by 1999, perhaps originally in reference to close games in sports, from the notion of biting one's fingernails as a sign of anxiety (attested from 1570s); see nail (n.) + bite (v.). Nail-biting (n.) is from 1805; nail-biter as "person who habitually or compulsively bites his fingernails" is by 1856.

"hand-tool used to trim the fingernails and toenails," 1890, from nail (n.) + clipper (n.).

"small, flat, single-cut file for trimming the fingernails," by 1823, from nail (n.) + file (n.2).

"lacquer applied to the fingernail or toenails to protect and decorate," 1881, from nail (n.) + polish (n.).

"workshop where nails are made," 1798, from nail (n.) + -ery or from nailer "one who makes nails" (mid-15c.) + -y (1).

"birth, origin," late 15c. (Caxton), from Middle French naissance "birth, parentage, place of origin" (12c.), present participle of naître, from Gallo-Roman *nascere, from Latin nasci "be born" (see genus).

"newly born or about to be born; rising or coming forth," originally a term in heraldry, 1570s, from French naissant, present participle of naître, from Gallo-Roman *nascere, from Latin nasci "be born" (see genus).

1650s, "natural, simple, unsophisticated, artless," from French naïve, fem. of naïf, from Old French naif "naive, natural, genuine; just born; foolish, innocent; unspoiled, unworked" (13c.), from Latin nativus "not artificial," also "native, rustic," literally "born, innate, natural" (see native (adj.)). In philosophy, "unreflecting, uncritical" (1895), used of non-philosophers. Related: Naively.

1670s, "a natural, unreserved expression of sentiments or thoughts," from French naïveté, from Old French naiveté "genuineness, authenticity," literally "native disposition" (see naive). From 1725 as "native simplicity." Englished form naivety is attested from 1708.

"to make naked," mid-14c., naken, from naked, perhaps with misapprehension of the -d as a past tense suffix. Marked as "Obs[olete] exc[ept] Sc[ottish]" in OED. Earlier was naken "to strip naked" (mid-13c.); a later generation coined nakedize (1858).