Where does “duochrome” come from?

duochrome (English) comes from English duo, from French duo, from Italian duo, from Latin duō, from Proto-Italic duō, from Proto-Indo-European dwóh₁ — two.

duochrome (English): The duochrome test, a test used by opticians to refine the correction of refractive error, in which the subject is asked to compare images presented with red and green backgrounds

Definitions

  1. The duochrome test, a test used by opticians to refine the correction of refractive error, in which the subject is asked to compare images presented with red and green backgrounds

Ancestry of “duochrome”, step by step

duochrome traces back through two separate lines of ancestry.

via English duo

StepLanguageWordMeaning
1EnglishduoTwo people who work or collaborate together as...
2Frenchduoduo; duet
3ItalianduoObsolete form of due; duo; duet
4Latinduōtwo; 2
5Proto-Italicduōtwo
6Proto-Indo-Europeandwóh₁two

via English chrome

StepLanguageWordMeaning
1EnglishchromeChromium, when used to plate other metals; The...
2Frenchchromechromium
3Ancient Greekχρῶμαskin (esp. the human body)
4Proto-Indo-Europeangʰreuto grind, rub
Every word from Proto-Indo-European dwóh₁ →