A great big pile of something is a heap. Your sloppy brother might keep all of his clothes in a heap on his bedroom floor.
A heap can be a literal mound of things — a heap of money in your piggy bank, or a heap of wet towels beside the pool — or it can be a figurative pile. For example, you might worry that if you're caught eating your roommate's pizza you'll be in a heap of trouble. Heap is also a verb, as when you heap compliments on your best friend. Since 1924 heap has also meant "junky old car."