1. To practice, run through, and prepare for a particular presentation or performance We're all busy rehearsing for the opening night of our play this Friday. You should rehearse for your speech on Monday. If you go out there and just read from your notes,

2. To practice one's delivery or performance of something ahead of a public presentation or exhibition. In this usage, a noun or pronoun is used between "rehearse" and "for." I'm rehearsing my speech for the conference tomorrow. We've been rehearsing a new comedy routine for the talent show.

3. To practice and prepare for a particular length of time. We've been rehearsing for hours—why don't we call it a day and start fresh tomorrow? You've been rehearsing for months, so you are going to absolutely smash it on opening night!

4. To practice one's delivery, presentation, or performance for a particular period of time. In this usage, a noun or pronoun is used between "rehearse" and "for." You can tell he rehearsed his speech for about five minutes before coming on the stage. The band has been rehearsing their new set list for weeks.