(pharmacology) A broad-spectrum macrolide antibiotic C₃₇H₆₇NO₁₃ produced by an actinomycete Saccharopolyspora erythraea (formerly Streptomyces erythreus) and similar in its effects to penicillin, administered orally or topically in the treatment of infections caused by Gram-positive bacteria.

plural of erythromycin