A hunch is a feeling or guess about something without having clear proof or evidence to back it up. When you have a hunch that it's going to rain even though the sky looks clear, or a hunch that your friend is planning a surprise, you're sensing something based on small clues your brain has noticed but can't quite explain.

Hunches come from experience and intuition working together. A detective might have a hunch about who committed a crime based on tiny details that don't quite add up. A chess player might have a hunch about their opponent's next move from recognizing a pattern. Your teacher might have a hunch that students didn't really understand yesterday's lesson, even if no one raised their hand to ask questions.

Scientists and inventors often follow hunches when exploring new ideas, though they know they'll need to test and prove their theories later. A hunch isn't the same as a wild guess: it's an educated feeling based on observation and experience, even when you can't point to exactly what tipped you off. Some hunches turn out wrong, but many lead to important discoveries or help people avoid problems they sensed coming.

As a verb, hunch can also mean to bend over or curl up, as in hunching your shoulders against the cold wind.