Alma Mater (n.) Look up Alma Mater at Dictionary.com
late 14c., Latin, literally "bountiful mother," a title Romans gave to goddesses, especially Ceres and Cybele, from alma, fem. of almus "nourishing," from alere "to nourish" (see old) + mater "mother" (see mother (n.1)). First used 1710 in sense of "one's university or school" in reference to British universities.