Anything that is difficult to understand or make sense of.
A game for one or more people that is more or less difficult to work out or complete.
A crossword puzzle.
A jigsaw puzzle.
A riddle.
Something made with marvellous skill; something of ingenious construction.
The state of being puzzled; perplexity.
To perplex (someone).
To think long and carefully, in bewilderment.
To make intricate; to entangle.