puzzle

Noun

• a game that tests your ingenuity

• a particularly baffling problem that is said to have a correct solution
  • he loved to solve chessmate puzzles
    
  • that's a real puzzler
    

Verb

• be uncertain about; think about without fully understanding or being able to decide
  • We puzzled over her sudden departure
    

• be a mystery or bewildering to
  • This beats me!
    
  • Got me--I don't know the answer!
    
  • a vexing problem
    
  • This question really stuck me
    

Related words

• Synonyms: 
  puzzler , mystifier , teaser , perplex , vex , stick , get , mystify , baffle , beat , pose , bewilder