1. to take on a task that is more than you can accomplish; to be greedy, overconfident, or too ambitious by taking on more jobs or responsibilities than you can deal with at one time

1. You can’t captain the team, edit the paper, and star in the play. Don’t bite off more than you can chew.

2. Ann is exhausted again. She’s always biting off more than she can chew.

3. I think he's bitten off more than he can chew taking all those classes.