A mismatch happens when two things don't fit together properly or aren't well suited for each other. When you try to wear one blue sock and one red sock, that's a mismatch. When a soccer team of beginners plays against professionals, that's also a mismatch: the skill levels are so different that the game won't be fair or competitive.

Things can mismatch in countless ways. A puzzle piece that doesn't belong creates a mismatch with the space you're trying to fill. When your expectations don't match reality, like imagining a party will be huge and exciting but finding only three people there, you've encountered a mismatch between what you hoped for and what actually happened.

The word often points to problems that need fixing. If your schedule mismatches your friend's schedule, you'll struggle to find time to hang out together. When someone's talents mismatch their job, they might feel frustrated or unsuccessful. Scientists talk about a mismatch when their experimental results don't line up with their predictions, which can lead to important new discoveries.

You can also use mismatched as an adjective: mismatched shoes, a mismatched pair of fighters, or mismatched expectations. Spotting mismatches helps you understand why something isn't working the way it should.