slang (originally U.S.). A hallucinatory experience induced by a drug, esp. LSD.

to freak out (occasionally without out): to undergo an intense emotional experience, to become stimulated, to rave, esp. under the influence of…

a trip (trip, n.1 5a) induced by acid.

An intense emotional experience, a ‘rave-up’, esp. one resulting from the use of hallucinatory drugs. (Also in more trivial uses.)

A hallucinatory experience or altered mental state induced by a (psychedelic) drug. Cf. trip, n.1 5a.

spec. of drug-induced hallucinations: see 5b of the verb.

The action or an instance of turning somebody on; a drug-taker's ‘trip’; something which or someone who arouses interest, enthusiasm, or sexual…