Noun | 1. | nystatin - an antifungal and antibiotic (trade names Mycostatin and Nystan) discovered in New York State; derived from soil fungi actinomycetes antibiotic, antibiotic drug - a chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections; "when antibiotics were first discovered they were called wonder drugs" antifungal, antifungal agent, antimycotic, antimycotic agent, fungicide - any agent that destroys or prevents the growth of fungi |