noun, noun or participle which takes 'suru'
heavy eating; eating like a horse
Describes eating a large amount of food, often with a nuance of voraciousness or gluttony. Can be used as a noun or with する to mean 'to eat heavily'.
彼は毎食馬食するが、全然太らない。
He eats like a horse at every meal, but never gains weight.
ストレスがたまると馬食してしまう。
When I'm stressed, I end up eating heavily.