If you leave an antique flowerpot outside all winter, the snow and rain might eat the paint, making it look even older than it is.
You probably know that eat means "to consume food," because you do that several times a day. But we also use the verb eat for other situations involving using something up or wearing it down. If your art project eats up all your art supplies, that means you don't have any left. Leaving your car lights on will eat through your battery. Something eating away at us is worrying us. Don't let money stress eat away at your happiness.