alma mater is a Latin expression that means "mother who feeds" or "the mother who nourishes", in the literal translation into Portuguese.
alma mater is a very common phrase to designate educational institutions that train their students intellectually, like universities, for example.
See also the meaning of University.
However, this term was used in Ancient Rome as a reference to the mother goddesses of the Romans, such as Venus, Ceres and Cybele.
During medieval Christianity, alma mater it was also used as an expression of reverence for the image of the Virgin Mary, mother of Jesus Christ.
Roman poets and other peoples who had Latin as their mother tongue, used this expression as a synonym for "my homeland", as it would be responsible for sheltering, defending and "nurturing" its citizens.
Returning to the typical meaning in contemporary times, alma mater came to be considered a second name for some universities. The University of Bologna, for example, is also known for Alma Mater Studiorum, which means “mother who nurtures studies”.