Find the word definition

Wiktionary
glycylcycline

n. (context medicine English) Any of a class of antibiotics related to the tetracyclines

Wikipedia
Glycylcycline

Glycylcyclines are a new class of antibiotics derived from tetracycline. These tetracycline analogues are specifically designed to overcome two common mechanisms of tetracycline resistance, namely resistance mediated by acquired efflux pumps and/or ribosomal protection. Presently, tigecycline is the only glycylcycline approved for antibiotic use.