adj. & n.
--adj.
1. a expanding the mind's awareness etc., esp. through the use of hallucinogenic drugs. b (of an experience) hallucinatory; bizarre. c (of a drug) producing hallucinations.
2 colloq. a producing an effect resembling that of a psychedelic drug; having vivid colours or designs etc. b (of colours, patterns, etc.) bright, bold and often abstract.
--n. a hallucinogenic drug.
Derivatives:
psychedelically adv.
Etymology: irreg. f. Gk (as PSYCHE, delos clear, manifest)