n.
Function: adjective
Date: 1957
1 a : of, relating to, or being drugs (as LSD) capable of producing abnormal psychic effects (as hallucinations) and sometimes psychotic states b : produced by or associated with the use of psychedelic drugs <a psychedelic experience>
2 : imitating, suggestive of, or reproducing effects (as distorted or bizarre images or sounds) resembling those produced by psychedelic drugs < psychedelic color schemes>
– psy · che · del · i · cal · ly \ - ' de-li-k( ə -)l ē \ adverb