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

British Dictionary definitions for spaced out

spaced out

adjective

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