1. a person or thing that perplexes; something that causes confusion or bewilderment
Usage: informal; relatively uncommon; more common in the form 'perplexing' (adjective)

Examples

• The math problem was a real perplexer for most of the class.
• That strange noise in the attic turned out to be quite a perplexer.
• The detective faced one perplexer after another in the case.
• His cryptic message was a perplexer that took days to decode.
• The ancient artifact remained a perplexer to archaeologists for years.