To perplex means to confuse or puzzle someone completely. When you're perplexed, you can't figure something out no matter how hard you try. You might feel perplexed by a riddle with no obvious answer, or perplexed when your friend suddenly stops talking to you for no reason you can understand.

Being perplexed is more than just a little confused. It's that bewildered feeling when something doesn't make sense at all. A detective might be perplexed by a mystery with contradictory clues. A student might be perplexed by a math problem that seems impossible to solve. The word suggests you're actively trying to understand something, but it keeps slipping away.

Something that perplexes you is perplexing. You might find your teacher's instructions perplexing if they seem to contradict each other. When you're in a state of confusion or bewilderment, you're in a state of perplexity. The key to the word is that feeling of being stumped: you want to understand, you're thinking hard about it, but the answer remains frustratingly out of reach.