pile 1 
(pīl)
(pīl)n.
1. A quantity of objects stacked or thrown together in a heap. See Synonyms at heap.
2. Informal
a. A large accumulation or quantity: a pile of work to do.
b. A large amount of money: made a pile in the real estate boom.
3. A nuclear reactor.
4. A voltaic pile.
5. A very large building or complex of buildings.
6. A funeral pyre.
v. piled, pil·ing, piles
v.tr.
1.
a. To place or lay in a pile or heap: piled books onto the table.
b. To load (something) with a heap or pile: piled the table with books.
2. To add or increase to abundance or to a point of burdensomeness: piled homework on the students.
v.intr.
Phrasal Verbs: 1. To form a heap or pile.
2. To move in, out, or forward in a disorderly mass or group: pile into a bus; pile out of a car.
pile on
1. To leap onto an existing pile of people, especially football players.
2. To add or increase (something, such as criticism) abundantly or excessively.
pile up
1. To accumulate: Work is piling up.
2. Informal To undergo a serious vehicular collision.
[Middle English, from Old French, from Latin pīla, pillar.]