macrolide
noun
mac·ro·lide
| \ ˈmak-rə-ˌlīd
\
\
Medical Definition of macrolide
: any of several antibiotics (as erythromycin or clarithromycin) that contain a usually 14- to 16-membered macrocyclic lactone ring, inhibit bacterial RNA-dependent protein synthesis, and are effective especially against gram-positive bacteria (such as staphylococci and streptococci)