Definition prom in American English

In the US, prom night is especially important to seniors (=students in their last year of high school). They buy expensive prom dresses or rent tuxedos (=formal men’s suits), give corsages (=flowers you wear on your dress or jacket) to their dates (=person you ask to go with you to the dance), and sometimes ride to the prom in a rented limo (=very long, expensive car).