The plural is “alumni” I believe.
Of course, my B.A. says “Memphis State University”, hence dating me for all eternity. :)
We have a granddaughter that has one of the same profs as her dad. He calls her his grandstudent.
The plural form is “alumni”. Singular form, feminine gender is “alumna”, while singular form, masculine gender is “alumnus”. In our days of PC, hardly anyone uses the feminine form, but, if I remember my Latin grammar, the plural, feminine is “alumnae”, which makes sense if one is talking about a group of female graduates.