Main Entry: tet·ra·cy·cline

Pronunciation: \ˌte-trə-ˈsī-ˌklēn\

Function: noun

Etymology: International Scientific Vocabulary tetracyclic having four fused hydrocarbon rings + ²-ine

Date: 1952

: a yellow crystalline broad-spectrum antibiotic C₂₂H₂₄N₂O₈ produced by streptomyces or synthetically; also : any of several chemically related antibiotics (as doxycycline)