To straighten means to make something straight that was bent, curved, or crooked. When you straighten a piece of wire, you remove its bends and curves until it forms a straight line. When you straighten your room, you arrange things neatly so it looks orderly instead of messy and scattered.

You might straighten your posture by sitting up tall instead of slouching, or straighten a picture frame that's hanging crooked on the wall. A carpenter straightens a board before cutting it. A teacher might ask students to straighten their desks into neat rows.

The word can also mean to resolve or fix a confusing situation. If two friends have a misunderstanding, they might need to straighten things out by talking honestly about what happened. When you straighten out a mix-up in your homework assignment, you're clearing up the confusion and getting back on track.

Sometimes people say they need to get straight on something, meaning they want to understand it clearly. If you're confused about the rules of a game, you might ask someone to help you get it straight so you know exactly how to play.