If you’re male, you’re an alumnus. A group of men is called alumni. If you’re female,
you’re an alumna. A group of women is called alumnae (pronounced “alum-nay”). If the
group is made up of both men and women, you’re alumni. That’s why you see “alumni”
most often; it can be gender neutral.
All of these terms come from the Latin words “alumnus,” which means “foster child,”
and “alere,” which means “to nourish.”