The story
- Proto-Indo-European*kʷetwóres
- Proto-Hellenic*kʷétwores
- Ancient Greekτέσσᾰρες (téssăres)
- Ancient Greekτετρᾰ- (tetră-)
- Englishtetra-
- Proto-Indo-European*kʷelh₁-redup.
- Proto-Indo-European*kʷékʷlos
- Proto-Hellenic*kʷókʷlos
- Proto-Hellenic*kúklos
- Ancient Greekκύκλος (kúklos)
- Ancient Greekκυκλῐκός (kuklĭkós)
- Classical Latincyclicu
- Middle Frenchcyclique
- Frenchcyclique
- Classical Latincyclicus
- Englishcyclic
- Englishtetracyclic
- English todaytetracycline
From tetracyclic + -ine.
Etymology from Wiktionary, CC BY-SA 4.0.