The story
- Proto-Indo-European*kelh₁-
- Proto-Indo-European*kl̥h₁rós
- Proto-Italic*klāros
- Latinclārus
- English(Streptomyces) erythr(eus)
- English(e)rythromycin
- English todayclarithromycin
From Latin clārus (“clear”) + English (e)rythromycin.
Etymology from Wiktionary, CC BY-SA 4.0.