Simple Definition of Achilles' heel
: a fault or weakness that causes or could cause someone or something to fail
Full Definition of Achilles' heel
: a vulnerable point
Examples of achilles' heel
I'm trying to lose weight, but ice cream is my Achilles' heel.
<the food supply proved to be the nation's Achilles' heel in its defense against terrorist attacks>
Origin of achilles' heel
from the story that Achilles was vulnerable only in the heel
First Known Use: 1840
Learn More about achilles' heel
Seen and Heard
What made you want to look up Achilles' heel? Please tell us where you read or heard it (including the quote, if possible).