The story
- Proto-Indo-European*per-der.?
- Proto-Indo-European*pér
- Proto-Indo-European*pró
- Proto-Italic*prō
- Latinprō
- Englishpro-
- Proto-Indo-European*h₁én
- Proto-Italic*en
- Proto-Italic*en-
- Latinin-
- Proto-Indo-European*bʰel-
- Proto-Italic*flagmā
- Latinflamma
- Latinflammō
- Latinīnflammō
- Latinīnflammātōrius
- Englishinflammatory
- English todayproinflammatory
From pro- + inflammatory.
Etymology from Wiktionary, CC BY-SA 4.0.