a collection of objects laid on top of each other
"The librarian carefully stacked the donated books into a neat pile in the corner of the room."
(often followed by `of') a large number or amount or extent
"a batch of letters"
"a deal of trouble"
"a lot of money"
"he made a mint on the stock market"
"see the rest of the winners in our huge passel of photos"
"it must have cost plenty"
"a slew of journalists"
"a wad of money"
battery consisting of voltaic cells arranged in series; the earliest electric battery devised by Volta
"Volta's famous pile consisted of alternating discs of zinc and silver coated with copper to create an early electric battery."
a nuclear reactor that uses controlled nuclear fission to generate energy
"The new pile in the research center began generating electricity after months of rigorous testing."
A mass of things heaped together; a heap.
"The pelt was thick and warm because it possessed such a dense pile of soft underfur."
A dart; an arrow.
A hemorrhoid.
Hair, especially when very fine or short; the fine underfur of certain animals. (Formerly countable, now treated as a collective singular.)
"She moved her pile of laundry to make more space on the floor."
place or lay as if in a pile
"The teacher piled work on the students until the parents protested"
To lay or throw into a pile or heap; to heap up; to collect into a mass; to accumulate
"The old man tried to pile his beard, but it only made him look more disheveled."
To drive piles into; to fill with piles; to strengthen with piles.
To give a pile to; to make shaggy.
In plain English: To pile something means to stack it up on top of other things until they form a messy heap.
"She piled her clothes on top of each other in the corner before packing them away for summer storage."
Usage: Use "pile" when describing the action of stacking items loosely on top of one another, such as piling laundry or snowdrifts. Avoid using it for neatly arranged stacks where you might prefer words like stack or arrange instead.
A surname.
"Captain Pile led his team to victory in the championship game."
The word comes to us via the Old French pile and ultimately derives from the Latin pīla, which originally meant "pillar" or "pier." It entered English through Middle English with this same sense of a vertical support structure.