To redo something means to do it again, usually because the first attempt didn't work out or wasn't good enough. When a teacher asks you to redo an assignment, you're starting over to improve it. When you redo your messy handwriting, you're rewriting it more clearly. When a carpenter redoes a crooked shelf, they're taking it apart and building it again the right way.

Sometimes you redo things by choice because you want better results. An artist might redo a painting that doesn't capture what they imagined. A cook might redo a recipe with different ingredients to improve the flavor. Other times you have to redo something because it failed: you might need to redo a science experiment that gave confusing results, or redo your room cleaning after realizing you just stuffed everything under the bed.

The word can also be a noun: if your bedroom gets a complete redo, everything gets rearranged and redecorated. Having to redo work can feel frustrating, but it's also how people improve and eventually master difficult skills. Almost every success story involves multiple redos along the way.