The story
- Proto-Indo-European*bʰeydʰ-
- Proto-Indo-European*bʰeydʰós
- Proto-Italic*feiðos
- Latinfoedus
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Frenchfédéral
- Frenchfédéralisme
- English todayfederalism
From French fédéralisme. By surface analysis, federal + -ism.
Etymology from Wiktionary, CC BY-SA 4.0.