puzzle

puzzle, perplex, bewilder, distract, nonplus, confound, dumbfound mean to baffle and disturb mentally.

puzzle implies existence of a problem difficult to solve.

perplex adds a suggestion of worry and uncertainty especially about making a necessary decision.

bewilder stresses a confusion of mind that hampers clear and decisive thinking.

distract implies agitation or uncertainty induced by conflicting preoccupations or interests.

nonplus implies a bafflement that makes orderly planning or deciding impossible.

confound implies temporary mental paralysis caused by astonishment or profound abasement.

dumbfound suggests intense but momentary confounding; often the idea of astonishment is so stressed that it becomes a near synonym of astound.

mystery, problem, enigma, riddle, puzzle mean something which baffles or perplexes.

mystery applies to what cannot be fully understood by reason or less strictly to whatever resists or defies explanation.

problem applies to a question or difficulty calling for a solution or causing concern.

enigma applies to utterance or behavior that is very difficult to interpret.

riddle suggests an enigma or problem involving paradox or apparent contradiction.

puzzle applies to an enigma or problem that challenges ingenuity for its solution.