spaced-out

or spaced

[ speyst-out or speyst ]
/ ˈspeɪstˈaʊt or speɪst /

adjective Slang.

dazed or stupefied because of the influence of narcotic drugs.
dreamily or eerily out of touch with reality or seemingly so; spacey.

Origin of spaced-out

1965–70, Americanism; on the pattern of phrasal verbs with out marking perfectivity; space apparently by association with “outer space” as, metaphorically, a place outside normal consciousness
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for spaced out

spaced out

adjective

slang intoxicated through or as if through taking a drugOften shortened to: spaced
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