flashback noun a relapse into a hallucinatory drug experience long after the effect of the drug has worn off US
— Edward R. Bloomquist, Marijuana, p. 339, 1971
— Home Office, GlossaryofTermsandSlangCommoninPenalEstablishments, July 1978
The myth of the flashback was widely promoted by the media and government as one of the severe dangers of LSD. — Cam Cloud, The LittleBookofAcid, p. 18, 1999