The story
- Proto-Indo-European*h₁én
- Proto-Italic*en
- Proto-Italic*en-
- Latinin-
- Proto-Indo-European*per-?
- Proto-Indo-European*pres-
- Proto-Italic*pres-
- Latinpremō
- Latinimprimō
- Latinimpressiōnem
- Frenchimpression
- Frenchimpressionner
- Frenchimpressionnable
- Englishimpressionable
- English todayimpressionableness
From impressionable + -ness.
Etymology from Wiktionary, CC BY-SA 4.0.