Use the adjective quondam if you need a fancy way to describe something as belonging to an earlier time. You might describe your quondam, or former, Latin tutor to your current Latin tutor, for example.
English has many ways of saying "former," including quondam, which is the word of choice if you want to sound a bit literary. You may be able to impress a quondam teacher, date, or employer with it. The word quondam comes directly from Latin, with the meaning of "formerly," and it's been used in English since the 1530's.