Wiktionary
drop acid
vb. (context slang English) to take LSD.
Usage examples of "drop acid".
As the coffee began to percolate, it occurred to her how easy it would be to do just that, drop acid, ketamine, PCP, Ecstacy, rat poison, kerosene or a dead cat into the cistern.
When morning comes, you bounce out of bed, remember who you are, swear you'll never drop acid again and thank everyone who took care of you.
There were over-age 'hippies' who still listened to the Beatles and migrated to the Altai Mountains to meditate and drop acid.