1. to be quarrelsome, aggressive, or rude; to be ready to fight

1. Avoid Calvin today. He has a real chip on his shoulder.

2. She’s not going to make any friends if she walks around with a chip on her shoulder like that.

3. I said good morning to Smith and he snapped back at me. He sure has a chip on his shoulder today.

4. Carl has a chip on his shoulder because he was passed over for promotion in favor of Maria, although he feels he was better qualified.