Completely sober; not intoxicated to any degree by drugs or alcohol. I'm stone sober, so I'll drive us home. No, I'm not high—I've been stone sober from the day I started working here!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
stone(–cold) soberand cold sober
absolutely sober. I am stone-cold sober, or I will be by morning anyway. I found the secret to waking up cold sober. Don't drink.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
See stone cold sober
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.