Where does “Firmin” come from?

Firmin is derived from Latin Firminus, which is derived from Latin Firmus, meaning strong or steadfast.

Ancestry of “Firmin”, step by step

Step	Language	Word	Meaning
1	Latin	Firminus	—
2	Latin	Firmus	—
3	Proto-Italic	fermos	—
4	Proto-Indo-European	dʰer-mo-s	holding
5	Proto-Indo-European	dʰer-	to support; to hold

Firmin — Etymology, Origin & Word History | Etymology Explorer