To stuff one's cheeks; to put a large amount of food into one's mouth at once.
子どもがパンを頬張って走り回っている。
The child is stuffing bread into his mouth and running around.
一口でケーキを頬張ったので、生クリームが飛び出した。
He stuffed a piece of cake into his mouth at once, and the whipped cream squirted out.
彼女はみかんを頬張りながらテレビを見ていた。
She was watching TV while stuffing a tangerine into her mouth.
お腹が空いていたので、パンを頬張いて食べた。
I was hungry, so I gulped down the bread.