Here's the breakdown:
* Alma: Latin for "nourishing" or "cherishing"
* Mater: Latin for "mother"
The phrase was originally used in ancient Rome to refer to a goddess who protected and nurtured her followers. Later, it came to be used for any female figure who provided care and guidance, particularly in the context of education.
It was first used in the context of universities in the Middle Ages to refer to the university itself, as a place that nurtured and educated students. This usage is still prevalent today, with "alma mater" being used to refer to the school or university one attended.