Achilles heel

or Achilles' heel

noun

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

   His Achilles heel is his quick temper.

Achilles heel

noun

1. a small but fatal weakness

Achilles' heel

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

Word History and Origins

Origin of Achilles heel¹

First recorded in 1800–10

Idioms and Phrases

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]

Example Sentences

Our visionary scientists have found the Achilles heel of yet another enemy of the State—the Superbug!

From The Daily Beast

Obama, extremely/quite confident: 32 percent Romney, extremely/quite confident: 19 percent That's the Achilles Heel, gang.

From The Daily Beast

It is already beyond repair in Yemen, the Achilles heel of Arabia where the police state has fractured and fallen apart.

From The Daily Beast

Signatures will not be his Achilles heel—he knows well how the game is played in this city.

From The Daily Beast

But it also represents the Achilles heel of a company that loves to look backward more than it does forward.

From The Daily Beast

These countries are the “Achilles heel of the British Empire.”

From Project Gutenberg