slang Sedative drugs, often barbiturates. Gorilla pills are dangerous, man—I'd stay away from them.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
See gorilla biscuits
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.