below the belt, hit

hit below the belt

To unfairly target another person's weakness or vulnerability. The phrase refers to boxing, in which hitting an opponent below the waist is unacceptable. I know she really wants the promotion, but she hit below the belt when she told the boss about my personal problems.
See also: below, belt, hit
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

below the belt, hit

Not behave according to the rules or decency, unfairly, as in Bringing up my mother's faults-that's really hitting below the belt. The term comes from boxing, where according to the Marquis of Queensberry Rules (1865) a fighter may punch his opponent only in the upper body or head. For a synonym, see low blow; also see under one's belt.
See also: below, hit
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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