also: ほうばる
godan verb (-ru), transitive verb
stuff one's cheeks; fill one's mouth
Used when someone puts a large amount of food in their mouth at once, making their cheeks bulge. Often implies eating eagerly or childishly.
子供がパンを頬張っている。
The child is stuffing his cheeks with bread.
あまり頬張ると喉に詰まらせるよ。
If you stuff your mouth too full, you'll choke.