slang Opium. Is it true that she used to be addicted to the big-O?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. opium. The big-O. is making a comeback, I hear.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.