Where does “photoplethysmograph” come from?

photoplethysmograph (English) comes from English photo-, from Ancient Greek φωτο-, from Ancient Greek φῶς, from Proto-Hellenic pʰáos, from Proto-Indo-European bʰéh₂os, from Proto-Indo-European bʰeh₂-, from Proto-Indo-European bʰeh₂-s-ri-.

photoplethysmograph (English): A plethysmograph that uses illumination of the...

Definitions

A plethysmograph that uses illumination of the...

Ancestry of “photoplethysmograph”, 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-	—

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