A silly little question—are there Latin terms for “Islam” or “Muslim”?
I mean, obviously, they wouldn’t be classical Latin words, but it’s not like they stopped developing or adding to the language when Rome fell. (Hell, as I remember, the Vatican came up with a Latin version of “AIDS,” a few years back!)
Rome is still there, the last time I looked at the map. The Latin language continued in common use in annals, etc., long after Mohammed’s time.
Islamicus is used for the adjective “Muslim” or “Islamic”, as in this article from Nuntii Latini. If this Latin Wikipedia article can be trusted, then the name of the religion is Religio Islamica, an adherent is a Musulmanus and the name of the prophet in Latin is Machometus. (Yes, there is a Latin wikipedia. I only just discovered it last month).
In gereral, the best place to look up the modern Latin words for modern concepts is a two-volume Italian-to-Latin dictionary called Lexicon Recentis Latinitatis edited by the late Carlo Egger. I’m afraid I don’t own a copy.
Medieval Latin terms for Muslims or Islamic peoples include “musulmanus” (“Muslim”), “morus” (“Moor”) and “turcus” (“Turk”); the latter two are originally ethnic designations for the people of the Islamic Andalusian and Ottoman Empires respectively, but were sometimes applied by extension to Muslims in general.