penicillin

noun

Etymology: Etymology tree Proto-Indo-European *pes- Proto-Indo-European *pes-ni-s Proto-Italic *peznis Latin pēnis Proto-Indo-European *-lós Proto-Indo-European *-elós Proto-Italic *-elos Proto-Italic *-kelos Latin -culus Latin pēniculus ▲ Proto-Italic *-elos Latin -lus Latin -illum Latin pēnicillum Translingual -ium Translingual Penicillium Proto-Indo-European *-nós Proto-Indo-European *-iHnos Proto-Italic *-īnos Latin -īnusder. Old French -inbor. Middle English -in English -ineclip. English -in English penicillin From translingual Penicillium + -in. Coined by Alexander Fleming after Penicillium notatum (now Penicillium chrysogenum), a fungus from which penicillin is obtained.

1. Any of a group of narrow-spectrum antibiotics obtained from Penicillium molds or synthesized, that have a beta-lactam structure and are active against gram-positive bacteria and used in the treatment of various infections and diseases.
2. A blue mold of the genus Penicillium that produces penicillin.