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psychedelia

[sahy-ki-deel-yuh, -del-yuh]
noun
  1. the realm or artifacts of psychedelic drugs, art, writings, or the like.

Origin of psychedelia

An Americanism dating back to 1965–70; psychedel(ic) + -ia
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for psychedelia

psychedelia

noun
  1. (functioning as singular or plural) psychedelic objects, dress, music, etc
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for psychedelia
n.

1967, from psychedelic + -ia.

Online Etymology Dictionary, © 2010 Douglas Harper