The story
- Proto-Indo-European*h₁én
- Proto-Indo-European*h₁énteros
- Latin*interus
- Latinintrā
- Englishintra-
- Englishmucosa
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Englishmucosal
- English todayintramucosal
Etymology from Wiktionary, CC BY-SA 4.0.