"action of sleeping," from Old English hneappunge, verbal noun from nap (v.).

also catnap, cat's nap, "a short, light sleep," by 1823, from cat (n.) + nap (n.). A nap such as a cat takes. As a verb from 1859.

"worn threadbare," 1590s, from nap (n.1) + -less.

"downy, having an abundance of nap on the surface," c. 1500, noppi, from nap (n.1) + -y (2). Earlier, of ale, "having a head, foamy" (mid-15c.), hence, in slang, "slightly intoxicated" (1721). Meaning "fuzzy, kinky," especially used in colloquial or derogatory reference to the hair of black people, is by 1840. It also was used of sheep. Related: Nappiness.