1 [computing] In computing, a data storage structure that operates on last in, first out (LIFO) protocol. As with a stack of dishes, the item placed on top of the stack last must be removed before the others may be manipulated.
2 [ESRI software] In MOLE, two or more force elements grouped together and placed one on top of another. Like leaders, stacks allow users to quickly make a map easier to read by allowing graphics to be grouped according to user-specified rules.