not put something past someone

not put (something) past (one)

1. To believe one is capable of doing something unsavory, immoral, illicit, selfish, etc. He's a very charming guy, but I wouldn't put it past him to stab me in the back if it meant advancing his career. I should know by now not to put such vile treachery past the likes of him.
2. To be unable to swindle, fool, or deceive one. My grandmother might be 85, but you still can't put a thing past her! That sleazy used car salesman couldn't put his bogus little scam past me.
See also: not, past, put
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

not put something past someone

Consider someone capable of doing something, especially something bad. For example, I wouldn't put it past him to tell a lie or two. This expression uses past in the sense of "beyond." [Late 1800s]
See also: not, past, put, someone, something
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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