an orderly pile
"The librarian carefully stacked the returned books on the shelf to keep them neat and accessible."
(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"
a list in which the next item to be removed is the item most recently stored (LIFO)
"The programmer organized the tasks into a stack so that the latest request would always be handled first."
a large tall chimney through which combustion gases and smoke can be evacuated
"The old factory still has a rusty stack towering over the skyline, puffing out gray smoke every morning."
a storage device that handles data so that the next item to be retrieved is the item most recently stored (LIFO)
"The programmer optimized the application by replacing the inefficient queue with a stack to ensure the last message sent was always the first one processed."
A pile.
"The delivery driver left a tall stack of cardboard boxes on my porch."
A large pile of hay, grain, straw, or the like, larger at the bottom than the top, sometimes covered with thatch.
"The farmer carefully arranged the freshly cut wheat into a tall stack in the field to protect it from rain before winter arrived."
In plain English: A stack is a pile of things that are all stacked on top of each other.
"The pile of dishes in the sink has formed such a high stack that I can barely reach the top plate."
To arrange in a stack, or to add to an existing stack.
"She carefully stacked the freshly baked cookies on the cooling rack before covering them with foil."
In plain English: To stack something means to pile it up on top of other things.
"Please stack these plates in the cupboard before you put them away."
Usage: Use this verb when physically piling items vertically so they rest on one another, such as stacking plates or firewood. It is often confused with the noun form of "stack," but here it specifically describes the action of arranging objects in a pile rather than simply adding to an existing list or data structure.
A surname.
"The Stack family has lived on that corner of the street for three generations."
The word "stack" comes from Old Norse stakkr, which originally meant a barn or haystack. Its modern meaning as a data structure is a direct translation of the Dutch word stapel that was introduced by computer scientist Edsger W. Dijkstra.