The story
- Proto-Indo-European*né
- Proto-Indo-European*n̥-
- Proto-Italic*n̥-
- Latinin-
- Latinir-
- English todayir-
From Latin ir-, assimilated form of in- used before r-.
Words from the same roots
Latinir- all →
irrefragableirrespirable
Etymology from Wiktionary, CC BY-SA 4.0.