Where does “phototherapy” come from?

Phototherapy comes from English therapy and Latin therapia, from Ancient Greek φῶς meaning light and θεραπεύω meaning to serve or attend, ultimately from Proto-Indo-European bʰeh₂-.

phototherapy (English): The use of light to treat disorders of the skin,...

Definitions

The use of light to treat disorders of the skin,...

Ancestry of “phototherapy”, step by step

Step	Language	Word	Meaning
1	English	photo-	light, electromagnetic radiation; photography
2	Ancient Greek	φωτο-	—
3	Ancient Greek	φῶς	Attic form of φᾰ́ος
4	Proto-Hellenic	pʰáos	—
5	Proto-Indo-European	bʰéh₂os	—
6	Proto-Indo-European	bʰeh₂-	to shine, glow light; to speak, say
7	Proto-Indo-European	bʰeh₂-s-ri-	—

Words derived from “phototherapy”

phototherapic
balneophototherapy

Every word from Proto-Indo-European bʰeh₂-s-ri- →Every word from Proto-Indo-European bʰeh₂- →Every word from Ancient Greek φωτο- →