Definitions of stack:

• noun:   an orderly pile
• noun:   a large tall chimney through which combustion gases and smoke can be evacuated
• noun:   (often followed by `of') a large number or amount or extent
• noun:   a storage device that handles data so that the next item to be retrieved is the item most recently stored (LIFO)
• noun:   a list in which the next item to be removed is the item most recently stored (LIFO)
• verb:   arrange the order of so as to increase one's winning chances

  Example: "Stack the deck of cards"

• verb:   arrange in stacks

  Example: "Stack your books up on the shelves"

• verb:   load or cover with stacks

  Example: "Stack a truck with boxes"

• name:  A surname (rare: 1 in 25000 families; popularity rank in the U.S.: #3474)