Achilles heel

American  

Or Achilles' heel

noun

1. a portion, spot, area, or the like, that is especially or solely vulnerable.

   His Achilles heel is his quick temper.

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Achilles heel British  

noun

1. a small but fatal weakness

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Achilles' heel Cultural  

1. A point of vulnerability. (See Achilles.)

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Achilles' heel Idioms  

1. A fatal weakness, a vulnerable area, as in This division, which is rarely profitable, is the company's Achilles' heel. The term alludes to the Greek legend about the heroic warrior Achilles whose mother tried to make him immortal by holding the infant by his heel and dipping him into the River Styx. Eventually he was killed by an arrow shot into his undipped heel. [c. 1800]

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Etymology

Origin of Achilles heel

First recorded in 1800–10

Example Sentences

Even China’s imports of crude, previously an Achilles heel given its heavy dependence on energy to fuel its economy, dropped 8.8% as electric vehicles continue to dominate the market for autos domestically.

From MarketWatch • Jan. 14, 2026

It's the Achilles heel of authoritarians throughout time.

From Salon • Nov. 15, 2024

The fighting mentality has been Napoli’s Achilles heel for several years.

From BBC • Oct. 29, 2024

A fungus devastating frogs and toads on nearly every continent may have an Achilles heel.

From Science Daily • Apr. 3, 2024

“An Achilles heel is a weakness, and you’ve got one.”

From "The Million Dollar Shot" by Dan Gutman