at (someone's or something's) mercy(redirected from at one's mercy)
at (someone's or something's) mercy
Subject to the control or actions of a particular person or thing. When you're a minor, you're totally at your parents' mercy. When you travel by public transportation, you're always at the weather's mercy. Her fate is at the jury's mercy—it's their decision now.
See also: mercy
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.