An alumnus is a male graduate of some institution, usually a college or university. An alumna is a woman graduate. Respective plurals are alumni and alumnae. The term alumni is now often used to refer to men and women graduates of coeducational institutions. To refer to graduates as alum or alums is nonstandard."Beth is an alumna of Smith College." "Barbara and Roberta are alumnae of Mount Holyoke College." "Jack is an alumnus of Duke University." "Joy, Jill, and Tom are alumni of Dartmouth College."
Dictionary of problem words and expressions. Harry Shaw. 1975.