Latin 'nourishing mother' — originally a goddess title, then applied to universities; 'alumni' are the nourished children.
The school, college, or university that one formerly attended; an anthem or song associated with a school or university.
From Latin 'alma māter' (nourishing mother), from 'almus' (nourishing, kind, bountiful, from 'alere,' to nourish) + 'māter' (mother), from Proto-Indo-European *h₂el- (to grow, to nourish) + *méh₂tēr (mother). Originally a Roman epithet for mother goddesses, especially Ceres and Cybele. Applied to universities from the 17th century, where the institution was imagined as a mother who nourishes students with knowledge. Key