The story
- Proto-Indo-European*upó
- Proto-Italic*supo
- Latinsub
- Latinsub-
- Englishsub-
- Proto-Indo-European*treb-der.?
- Ancient Greekθερᾰ́πων (therắpōn)
- Ancient Greekθεραπεύω (therapeúō)
- Ancient Greekθερᾰπευτής (therăpeutḗs)
- Ancient Greekθεραπευτικός (therapeutikós)
- New Latintherapeuticus
- Middle Englishterapeucia
- Englishtherapeutic
- English todaysubtherapeutic
From sub- + therapeutic.
Etymology from Wiktionary, CC BY-SA 4.0.