The story
- Proto-Indo-European*né
- Proto-Indo-European*n̥-
- Proto-Italic*n̥-
- Latinin-
- Middle Englishin-
- Englishin-
- Proto-Indo-European*h₂ewg-
- Proto-Indo-European*h₂owg-éye-ti
- Proto-Italic*augejō
- Proto-Italic*augeō
- Latinaugeō
- Latinauctor
- Latinauctōritā
- Old Frenchautorité
- Middle Englishauctorite
- Englishauthorit(y)
- Englishauthoritative
- English todayinauthoritative
From in- + authoritative.
Etymology from Wiktionary, CC BY-SA 4.0.