An alum is a former student of a particular school or college. When someone graduates from a university and later returns to speak at an event, they're introduced as an alum of that institution.

Schools often stay connected with their alums, inviting them back for reunions or asking them to mentor current students. A successful scientist might return to her old elementary school as an alum to inspire younger students interested in science. Universities track their alums and celebrate their achievements, whether they become teachers, engineers, artists, or anything else.

The word can also refer to a group: the alumni (pronounced uh-LUM-nye) are all the former students of a school. Your parents might attend an alumni gathering at their old college to reconnect with classmates they haven't seen in years. Being part of a school's alumni group means you'll always have that connection to the place where you learned and grew.