off (one's) chump(redirected from off their chump)
off (one's) chump
Crazy or insane. He must be off his chump to pay that much money for that old car. Am I completely off my chump for starting a business in this economy?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
off your chumpcrazy. British informal
The literal sense of chump meaning ‘a broad, thick block of wood’ led in the mid 19th century to its humorous use to mean ‘head’, with the implication of ‘blockhead’.
Farlex Partner Idioms Dictionary © Farlex 2017
off one’s chump
mod. crazy; nuts. Am I off my chump, or did that car suddenly disappear?
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.