means A neat pile of things laid one atop another, or in computing a memory structure where the last item added is the first one removed.

from From Old Norse 'stakkr,' a haystack — those great heaps farmers built against the sky. The word sailed into English with the Vikings, kept its sense of 'orderly pile,' and centuries later the computer scientists borrowed it for their last-in-first-out structure, picturing data piled up like hay, the top bale always grabbed first.