Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An antibiotic drug obtained from molds especially of the genus Penicillium or produced synthetically, available in various preparations and usually used to treat infections caused by gram-positive bacteria.
  • noun Any of a group of broad-spectrum antibiotic drugs, synthetic or semisynthetic, that are derived from penicillin.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Chem.) Any of a variety of substances having a structure containing a beta-lactam ring fused to a thiirane ring, to which a carboxyl group is attached, but most commonly interpreted as benzyl penicillin. They are notable as powerful antibacterial agents of relatively low toxicity which have found extensive use in medicine for treating bacterial infections. They are categorized as one of the classes of beta-lactam antibiotic. They are produced naturally by some fungi and bacteria, and industrial production processes almost invariably start from some form of the penicillin nucleus produced by fermentation of microorganisms. The fermentation products are then chemically modified to produce derivatives of enhanced potency, safety, or antibacterial spectrum. The first penicillin to see extensive use clinically (during World War II) was penicillin G, also called benzypenicillin, and commonly simply “penicillin”.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun pharmacology Any of a group of broad-spectrum antibiotics obtained from Penicillium molds or synthesized; they have a beta-lactam structure; most are active against gram-positive bacteria and used in the treatment of various infections and diseases.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun any of various antibiotics obtained from Penicillium molds (or produced synthetically) and used in the treatment of various infections and diseases

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[penicill(ium) + –in.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

Coined by Alexander Fleming after New Latin Penicillium notatum (now Penicillium chrysogenum), a fungus from which penicillin is obtained.

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  • paintbrush or brushedpaint etymologically

    March 6, 2009

  • 1928 Alexander Fleming, from random mold that flew in dish. Later cultured from green mold on grapefruit. not discovered from a lead compound, it is the lead compound.

    January 21, 2011