eat food accompanied by lots of liquid; also use metaphorically; "She washed down her dinner with a bottle of red wine"; "He washes down his worries with a nightly glass of whisky
If you wash down an object, you wash it all, from top to bottom. The prisoner started to wash down the walls of his cell
If you wash something, especially food, down with a drink, you drink the drink after eating the food, especially to make the food easier to swallow or digest. He took two aspirin immediately and washed them down with three cups of water