I'm wondering what does it mean to chomp in your sleep?

Bruxism/grinding: Someone may grind their teeth for a number of reasons. Often, the problem occurs because the muscles of the face and jaw are trying to get the teeth in a comfortable position. The muscles may be in spasm, you may have a tmj/tmd problem, stress, infection. Best to see a dentist asap. Often thew cause is difficult to determine, so may have to treat the symptoms with a mouthpiece.