I don't believe you; that's not true. A: "I once caught a fish that was longer than you are tall! I, uh, just didn't have the heart to kill such a majestic creature." B: "Yeah, right, Bill. Whatever you say." A: "Sarah said she was going to clean her room this weekend." B: "Ha, yeah, right! I'll believe it when I see it."
See also: right
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
exclam. the ultimate sarcastic response of disbelief. Yeah, right! You were just going through my desk looking for a pencil.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.