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*(s)tey-?
- Latinstimulus
- Latinstimulo
- Latinstimulatus
- Englishstimulate
- Englishstimulated
- English todayunstimulated
From un- + stimulated.
Etymology from Wiktionary, CC BY-SA 4.0.