Alumnus
Part of speech: noun
Definition: a male pupil or student a male graduate a student a graduate
Alum
Part of speech: noun
Definition: the double sulphate of potassium and aluminium with chemical formula K2SO4.Al2(SO4)3.24H2O.Any similar double sulphate in which either or both of the potassium and aluminium is wholly or partly replaced by other univalent or tervalent cations.A graduate of a university or other institution.