acid-head

or ac·id·head

[ as-id-hed ]
/ ˈæs ɪdˌhɛd /

noun Slang.

a person who habitually takes the drug LSD.

Origin of acid-head

First recorded in 1965–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019