lose reason(redirected from losing their reason)
To become insensible; to lose the ability to think rationally or logically; to be unable to reason. A possessive pronoun can be used between "lose" and "reason." My brain was so addled with drugs that I completely lost reason. What is going on with the boss's decisions lately? It's like she's lost her reason.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
lose one's reason
Fig. to lose one's power of reasoning, possibly in anger. I was so confused that I almost lost my reason. Bob seems to have lost his reason when he struck John.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.