To feed someone is to give them something to eat. Part of your daily morning routine might be remembering to feed your cat.
When you feed a dog, you put food in his bowl, and when you feed your extended family, you might cook them a Thanksgiving feast. Animals are sometimes said "to feed," or to consume or eat, and you can also use the word to mean "food for an animal," or "to supply or promote." The Old English root is fedan, "nourish, sustain, or foster."