n. & v.
n. 1 a pile or heap, esp. in orderly arrangement. 2 a circular or rectangular pile of hay, straw, etc., or of grain in sheaf, often with a sloping thatched top, a rick. 3 colloq. a large quantity (a stack of work; has stacks of money). 4 a = chimney-stack. b = SMOKESTACK. c a tall factory chimney. 5 a stacked group of aircraft. 6 (also stack-room) a part of a library where books are compactly stored, esp. one to which the public does not have direct access. 7 Brit. a high detached rock esp. off the coast of Scotland and the Orkneys. 8 a pyramidal group of rifles, a pile. 9 Computing a set of storage locations which store data in such a way that the most recently stored item is the first to be retrieved. 10 Brit. a measure for a pile of wood of 108 cu. ft. (30.1 cubic metres).
v.tr. 1 pile in a stack or stacks. 2 a arrange (cards) secretly for cheating. b manipulate (circumstances etc.) to one's advantage. 3 cause (aircraft) to fly round the same point at different levels while waiting to land at an airport. stack arms hist. = pile arms. stack up US colloq. present oneself, measure up. stack-yard an enclosure for stacks of hay, straw, etc. stackable adj. stacker n.
[ ME f. ON stakkr haystack f. Gmc ]