The story
- Proto-Indo-European*h₂éd
- Proto-Italic*ad
- Proto-Italic*ad-
- Latinad-
- Proto-Indo-European*gʰredʰ-
- Latingradior
- Latinaggredior
- Latinaggressu
- Englishaggress
- Englishaggressive
- English todayaggressiveness
From aggressive + -ness.
Etymology from Wiktionary, CC BY-SA 4.0.