put the (old) feedbag on
slang To begin eating; to have a meal. "Feedbag" is sometimes spelled as two words. I can't wait to get to grandma's and put the old feedbag on. She always cooks the tastiest food! What do you say we put the feed bag on before we head out?
put the feed bag on
and put the nose-bag onFig. to eat a meal. (Both refer to a method of feeding a horse by attaching a bag of food at its nose and mouth.) It's time to put the feed bag on! I'm starved! When do we put on the nose-bag?