Word Origin & History
1560s, "sudden turn of mind," perhaps related to O.E. frician "to dance" (not recorded in M.E., but the word may have survived in dialect), or perhaps from M.E. frek "bold, quickly," from O.E. frec "greedy, gluttonous." Sense of "capricious notion" (1560s) and "unusual thing, fancy" (1784) preceded that
in freak of nature (1847). The sense in health freak, ecology freak, etc. is attested from 1908. The verb meaning "change, distort" goes back to 1911.
also freakout bad psychedelic drug trip or something comparable to one, 1966 (despite an amusing coincidental appearance of the phrase dug up by the OED for 1749), from verbal phrase freak out, attested from 1965 in the drug sense; see freak
. Freak (n.) "drug user" is attested from 1945.