jigsaw puzzle

noun

1. Also called picture puzzle. a set of irregularly cut pieces of pasteboard, wood, or the like that form a picture or design when fitted together.
2. any complex, confusing situation, condition, or item, as one composed of seemingly diverse or unrelated elements.

noun

1. a puzzle in which the player has to reassemble a picture that has been mounted on a wooden or cardboard base and cut into a large number of irregularly shaped interlocking pieces