It is well-known that the English language has borrowed a lot of words from other languages throughout the centuries. Most of these have a meaning that is either the same as in the original language or is slightly modified for figurative reasons - e.g. the word robot (borrowed from the sci-fi plays of a Czech author) literally means a "worker" or the word cannibal (inspired from the endonym Caniba of an indigenous tribe in the Caribbeans, which practiced man-eating) meant in the original language a "human".
There is though a minority of foreign words, usually of Latin origin, whose meaning in English was once the same as in the primary language but eventually has changed due to frequent incorrect usage. A notorious example for this is the phrase:
which principally should be:
Someone is graduated...
since the action of graduation is performed by the education body, not by the student.
My question in this relation is how one should apply such foreign words (with an altered, dubious meaning) - in the "proper, but archaic" or in the "improper, but well-established" way?
PS The main motivation for my inquiry is the phrase fresh alumnus, which I'd like to use in the sense "recently graduated (male) student" in a letter to the Head of School of my former college... What bothers me is that the word alumni in Latin referred to any student (graduated or not) / member of staff of an institution, so I worry that fresh alumnus may be perceived as a "recently accepted (male) student".