The school or university from which one graduated. The term also refers to a school's official song: “The reunion began with everyone singing the alma mater.” From Latin, meaning “nurturing mother.”
1398, from L., lit. "bountiful mother," title Romans gave to goddesses, especially Ceres and Cybele, from alma, fem. of almus "nourishing," from alere "to nourish" (see old) + mater "mother." First used 1710 in sense of "one's university or school" in ref. to British universities.