Question

Chip on Your Shoulder to be quarrelsome, aggressive, or rude; to be ready to fight

Accepted Answer

Avoid Calvin today. He has a real chip on his shoulder. In the early 1800s American boys played the following game: One boy put a chip of wood or stone on his shoulder and dared another boy to knock it off. If he did, the two boys would fight. Today, if a person is edgy or looking for an argument, we say that he has a "chip on his shoulder," in reference to that old game.

Idiom	Chip on Your Shoulder
Example	Avoid Calvin today. He has a real chip on his shoulder.
Meaning	to be quarrelsome, aggressive, or rude; to be ready to fight
Origin	In the early 1800s American boys played the following game: One boy put a chip of wood or stone on his shoulder and dared another boy to knock it off. If he did, the two boys would fight. Today, if a person is edgy or looking for an argument, we say that he has a "chip on his shoulder," in reference to that old game.

Chip Shoulder Boys Avoid Calvin Today Real Quarrelsome