freak out (n.) Look up freak out at Dictionary.com
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 in "Fanny Hill" from 1749), 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.). Freak (n.) "drug user" is attested from 1945.
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]