The story
- Proto-Indo-European*né
- Proto-Indo-European*n̥-
- Proto-Germanic*un-
- Proto-West Germanic*un-
- Old Englishun-
- Middle Englishun-
- Englishun-
- Proto-Indo-European*tres-
- Proto-Indo-European*troséyeti
- Proto-Italic*troseō
- Latinterreō
- Proto-Indo-European*dʰeh₁-
- Proto-Italic*θakos
- Latinterrificus
- Frenchterrifique
- Englishterrific
- English todayunterrific
Etymology from Wiktionary, CC BY-SA 4.0.