nystatin: an antifungal and antibiotic (trade names Mycostatin and Nystan) discovered in New York State; derived from soil fungi actinomycetes
antibiotic: a chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections
parity: (physics) parity is conserved in a universe in which the laws of physics are the same in a right-handed system of coordinates as in a left-handed system