at the mercy of

Idioms  

1. Also, at someone's mercy . Subject to the power of, helpless against, as in The captured rebels were at the mercy of the army commander . [Late 1500s]

2. Without any protection against, as in On top of Mount Washington we were at the mercy of the elements . [Late 1600s]

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Example Sentences

"Insects are cold-blooded, so they are at the mercy of external temperatures," said Northwestern's Marco Gallio, who led the study.

From Science Daily • Mar. 26, 2026

The main risk is that by locking your money away in exchange for a monthly income at a predetermined interest rate, you are at the mercy of a massive surge in inflation and interest rates.

From MarketWatch • Mar. 24, 2026

However, the shares remain entirely at the mercy of oil prices.

From Barron's • Mar. 10, 2026

"But it's a long, drawn-out situation and we're at the mercy of the Police Scotland and the Registers of Scotland's office," he said.

From BBC • Mar. 10, 2026

I can’t just give up and leave Autumn and Ama at the mercy of Nansi.

From "Kwame Crashes the Underworld" by Craig Kofi Farmer