macrolide

noun

mac·​ro·​lide ˈmak-rə-ˌlīd 

: 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)