Definitions
1.NounA box that cannot be opened by the usual obvious means, and therefore challenges a person to find the correct way to open it.
2.NounA similar device or cage that can be opened by means of levers, latches, etc., used to test the learning behaviour of animals.
3.NounSomething that is puzzling; an enigma; a complex story that is gradually revealed, often driven by a central myth."puzzle box show; puzzle-box plot"
4.NounA box containing a jigsaw puzzle.