What does "stack" mean?

Additional senses

1. 2.A pile of wood containing 108 cubic feet. [Eng.]
2. 3.(Arch.) (a) A number of flues embodied in one structure, rising above the roof. Hence: (b) Any single insulated and prominent structure, or upright pipe, which affords a conduit for smoke; as, the brick smokestack of a factory; the smokestack of a steam vessel. (Computer programming) (a) A section of memory in a computer used for temporary storage of data, in which the last datum stored is the first retrieved. (b) A data structure within random-access memory used to simulate a hardware stack, as, a push-down stack. Stack of arms (Mil.), a number of muskets or rifles set up together, with the bayonets crossing one another, forming a sort of conical self-supporting pile.
3. 4.To lay in a conical or other pile; to make into a large pile; as, to stack hay, cornstalks, or grain; to stack or place wood. To stack arms (Mil.), to set up a number of muskets or rifles together, with the bayonets crossing one another, and forming a sort of conical pile.