To rehearse means to practice something before performing it for real. When a school play rehearses, the actors run through their lines, practice their movements, and work out any problems before opening night. Musicians rehearse a concert, athletes rehearse plays, and speakers rehearse presentations.

The word captures the idea of preparation through repetition. You might rehearse a speech in front of a mirror, trying out different ways to explain your main points. A band rehearses together so everyone learns their own part and how all the instruments fit together. During rehearsal, mistakes are expected and even helpful because they show what needs more work.

Rehearsing is different from just thinking about what you'll do. It means actually doing it, ideally in conditions similar to the real situation. When something goes well-rehearsed, people can tell: the presentation flows smoothly, the team executes their plan confidently, and problems get handled calmly because they've been worked through before.

A rehearsal is the practice session itself. Theater productions typically have many rehearsals before the opening performance, each one helping the cast and crew work together more smoothly.