To be under the influence of lysergic acid diethylamide (LSD), a powerful psychedelic drug commonly known as "acid." A lot of my friends like being on acid, but it just makes me feel really tense and paranoid.

Under the influence of lysergic acid diethylamide (LSD), a powerful psychedelic drug commonly known as "acid." The man was reportedly on acid when claimed he could fly and tried to jump off the building.