psy‧che‧del‧ic /ˌsaɪkəˈdelɪk◂, ˌsaɪkɪˈdelɪk◂/ adjective [usually before noun]
[Date: 1900-2000; Language: Greek; Origin: psych- ( ⇒ psych-) + deloun 'to show']

1. psychedelic drugs such as LSD make you hallucinate (=see things that do not exist)

2. having or using bright colours or strange sounds, and representing the experiences people have when they use drugs such as LSD:
a psychedelic light show
Fashion designers look back to the 1960s with dazzling psychedelic prints.
—psychedelically /-kli/ adverb
—psychedelia /-ˈdiːliə/ noun [uncountable]:
sixties psychedelia

[TahlilGaran] Dictionary of Contemporary English ▲