c.1374, "to show signs of madness or delirium," from O.Fr.
raver, variant of
resver "to dream, wander, rave," of unknown origin (see
reverie). The identical (in form) verb meaning "to wander, stray, rove" first appeared c.1300 in Scottish and northern dialect, and is probably from an unrelated Scand. word (cf. Icelandic
rafa). Sense of "talk enthusiastically about" first recorded 1704. Noun meaning "rowdy party" is from 1960, though
rave-up was British slang for "wild party" from 1940; specific modern sense of "mass party with loud, fast electronic music and often psychedelic drugs" is from 1989.
Raver, from this sense, is first recorded 1991.
Raving is attested from 1475; sense of "remarkable" is from 1841.
[reyv] 
verb, raved, rav⋅ing, noun, adjective 