The story
- Proto-Indo-European*h₁én
- Proto-Indo-European*h₁n̥tér
- Proto-Italic*n̥ter
- Latininter
- Latininter-
- Englishinter-
- Proto-Indo-European*wers-
- Proto-Germanic*werzaną
- Proto-West Germanic*werʀan
- Frankish*werʀ
- Early Medieval Latinwerra
- Old Northern Frenchguerre
- Old Englishwerre
- Middle Englishwerre
- Englishwar
- English todayinterwar
Etymology from Wiktionary, CC BY-SA 4.0.