Achilles Heel

Many modern English idioms come from the time of the ancient Greeks or Romans. Achilles heel is one of them.

Meaning of Idiom ‘Achilles Heel’

An Achilles heel is a person’s (organization, country, etc.) weakness or vulnerability. Although it can refer to a physical weakness or limitation, this idiom can refer to any perceived weakness. It may also refer to someone who is successful, strong, or otherwise doing well, but which has one ‘fatal flaw’ or weakness which could bring about their failure or downfall. The weakness or flaw doesn’t necessarily have to negative, in general.

Want to see more videos from Idioms.Online? Subscribe to our YouTube channel!


This idiom is used in jest as much as it is used seriously. For instance, a person might say “Ice cream is my Achilles heel,” even though they have no intention of saying that ice cream will be their ‘downfall.’

Thetis dipping Achilles into the River Styx, creating achilles heel
c. 1630-1635. Thetis dipping infant Achilles into the River Styx,
holding him by the heel, which became his one
vulnarable spot
Artist Peter Paul Reubens around 1630/1635 as part of the Achilles Series,
part of the Museum Boijmans Van Beuningen, Rotterdam

Other Examples

“The mayor’s womanizing was his Achilles heel.”

“The team had an Achilles heel, their inexperienced outfielder.”

“Gambling was his Achilles heel.”

“Martin’s selflessness proved to be his Achilles heel.”

Origin of the Idiom

This idiom comes from Greek mythology. Achilles was a great Greek warrior who was invulnerable in battle, or almost. He was the son of the Nymph, Thetis.

Thetis was married to Peleus. According to some stories, this marriage was unhappy and against her will. Since Peleus was a mortal, this meant Achilles was only semi-divine. As if this wasn’t bad enough, when Achilles was still an infant, Thetis became aware that Achilles was destined to die early at Troy. She hatched a plan to keep him alive.

In one of many stories, Thetis took Achilles to the River Styx and dipped him in the waters. The waters made Achilles invulnerable and gave him great strength. However, to dip him in the water, Thetis held him by his heel. Therefore, his heel did not get wet and was not made invulnerable like the rest of his body. This became his one weak spot.

In truth, the river dipping was only one of many attempts by Thetis to prevent her Son’s early death. But his heel became his downfall during the battled Trojan War. Paris, the Prince of Troy, fired an arrow through his heel, his one vulnerable spot, which killed him.

Note that this story is a later addition to the Achilles legends. He was not invulnerable in all stories.

Achilles not only lent his name to an idiom but to a part of the human anatomy. The Achilles tendon is the very prominent and tough band of tissue that connects the heel bone (calcaneus) to the calf muscles. Just as it was for Achilles, this area is vulnerable for all of us, as many people suffer a rupture of this tendon during sports activities or exercise, especially after the age of 30.

More Idioms Starting with A

More Mythology Idioms

More Proper Name Idioms

This page contains one or more affiliate links. See full affiliate disclosure.


YouTube and Facebook Group