Perplexity is the feeling of being confused and uncertain because something is complicated or puzzling. When you're in a state of perplexity, you might scratch your head, furrow your brow, or stare at a problem wondering where to even begin.

You might feel perplexity when trying to solve a particularly tricky math problem that seems to have no clear path to the answer. A detective examining contradictory clues at a crime scene experiences perplexity. When you read a passage in a book and realize you have no idea what just happened, that's perplexity.

The word implies that you're actively thinking hard about something that resists easy understanding. You're puzzled, your mind working to untangle something that stays knotted. A student might look at their teacher in perplexity after hearing instructions that seem to contradict each other.

Something that causes this feeling is perplexing. A magic trick is perplexing because you can't figure out how it works. A friend's sudden mood change might be perplexing if you can't understand what caused it.