Words related to freak

fresh (adj.2)
"impudent, presumptuous," or as Century Dictionary puts it, "verdant and conceited," 1848, U.S. slang, probably from German frech "insolent, cheeky," from Old High German freh "covetous," related to Old English frec "greedy, bold" (see freak (n.2)).
freakish (adj.)
1650s, "capricious," from freak (n.) + -ish. Meaning "grotesque" is recorded from 1805. Related: Freakishly; freakishness. Keats has freakful.
freak-out (n.)

also freakout "bad psychedelic drug trip," or something comparable to one, 1966, from verbal phrase freak out, attested from 1965 in the drug sense (from 1902 in a sense "change, distort, come out of alignment"); see freak (n.). There is a coincidental appearance of the phrase in "Fanny Hill:"

She had had her freak out, and had pretty plentifully drowned her curiosity in a glut of pleasure .... [Cleland, "Memoirs of a Woman of Pleasure," 1749]

where the sense is "she had concluded her prank."

freaky (adj.)
1824, "capricious, whimsical," from freak (n.) + -y (2). Psychedelic sense is from 1966. Related: Freakiness.