1. (n.) A large pile of hay, grain, straw, or the like, usually of a nearly conical form, but sometimes rectangular or oblong, contracted at the top to a point or ridge, and sometimes covered with thatch.

2. (n.) A pile of poles or wood, indefinite in quantity.

3. (n.) A pile of wood containing 108 cubic feet.

4. (n.) A number of flues embodied in one structure, rising above the roof. Hence:

5. (a.) 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.

6. (n.) A section of memory in a computer used for temporary storage of data, in which the last datum stored is the first retrieved.

7. (n.) A data structure within random-access memory used to simulate a hardware stack; as, a push-down stack.

8. (n.) 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.