1. people who use LSD or other hallucinogenic drugs, especially as a recreational habit
Usage: slang; informal; chiefly 1960s counterculture

Examples

• The acidheads gathered at the concert to experience the music in an altered state.
• During the 1960s, acidheads were a visible part of the counterculture movement.
• The documentary featured interviews with former acidheads reflecting on their experiences.
• Acidheads often sought out psychedelic art and music that complemented their drug use.