bite off more than can chewbite off more than (you) can chew
informal to try to do more than you are able to do.
Don't bite off more than you can chew. Let someone else organize the party.
bite off more than (one) can chew
To take on more responsibility than one can handle. I bit off more than I could chew when I volunteered to manage three little league teams in one season.
bite off more than (one) can chew
To decide or agree to do more than one can finally accomplish.