perplexer

/pərˈplɛksər/
noun
  1. A person or thing that causes confusion or puzzlement.
    • The math problem was a real perplexer for the whole class.
    • The detective stared at the note, calling it a perplexer that didn't fit the case.
    • Her sudden change of plans was a perplexer to everyone who knew her.
Antonyms