The story
- Proto-Indo-European*h₃reǵ-
- Proto-Indo-European*h₃rḗǵs
- Proto-Italic*rēks
- Latinrēx
- Frenchrexisme
- English todayRexism
Semi-learned borrowing from French rexisme. By surface analysis, Latin rēx + English -ism.
Etymology from Wiktionary, CC BY-SA 4.0.