penicillin

noun

pen·​i·​cil·​lin ˌpe-nə-ˈsi-lən 

1

: any of several relatively nontoxic antibiotic acids of the general formula C₉H₁₁N₂O₄SR that are produced by molds (genus Penicillium and especially P. notatum or P. chrysogenum) or synthetically and are used especially against gram-positive cocci

also : a mixture of such acids

2

: a salt or ester of a penicillin or a mixture of such salts or esters

Examples of penicillin in a Sentence

Recent Examples on the Web

Pfizer is the nation’s sole supplier of the penicillin shot. —Bymike Stobbe, Fortune Well, 8 Nov. 2023

However, this changed with the discovery of penicillin, the first antibiotic. —Delaney Nothaft, USA TODAY, 7 Aug. 2023

In reality, 95 percent of those diagnosed with a penicillin allergy aren’t actually allergic. —Andrew Chapman, Scientific American, 5 Oct. 2023

Pfizer's penicillin products have been in shortage since April. —Fox News, 13 June 2023

Although penicillin is the drug of choice to treat Treponema pallidum, the causative agent of syphilis, many health care providers are currently using doxycycline as an alternative to treat the infection because of the national shortage of penicillin. —Shiv Sudhakar, Fox News, 8 Oct. 2023

When Magalhães contracted the same disease as a child, he was cured with a simple dose of penicillin. —Bill Gifford, Scientific American, 31 July 2023

The most common medications people experience allergies to include penicillin, antibiotics, sulfa drugs, anticonvulsants, and aspirin, ibuprofen and other nonsteroidal anti-inflammatory drugs, according to the American College of Allergy, Asthma,and Immunology. —Lisa Mulcahy, Men's Health, 29 Aug. 2023

Aspartame had a shady start Like many momentous scientific discoveries (penicillin, Botox, pineapple on pizza, probably), aspartame was discovered by accident. —Sam Stone, Bon Appétit, 18 July 2023

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Word History

Etymology

New Latin Penicillium

First Known Use

1929, in the meaning defined at sense 1

Kids Definition

penicillin

noun

pen·​i·​cil·​lin ˌpen-ə-ˈsil-ən 

: any of several antibiotics or a mixture of these produced by penicillia or in the laboratory and used especially against round disease-producing bacteria

Etymology

from scientific Latin Penicillium "a genus of molds producing antibiotics," from Latin penicillus, literally, "little tail" — related to pencil

Medical Definition

penicillin

noun

pen·​i·​cil·​lin ˌpen-ə-ˈsil-ən 

1

: a mixture of relatively nontoxic antibiotic acids produced especially by molds of the genus Penicillium (as P. notatum or P. chrysogenum) and having a powerful bacteriostatic effect against various chiefly gram-positive bacteria (as staphylococci, gonococci, pneumococci, hemolytic streptococci, or some meningococci)

2

: any of numerous often hygroscopic and unstable amido acids (as penicillin G, penicillin O, and penicillin V) that have a structure in which a four-membered lactam ring shares a nitrogen and a carbon atom with a thiazolidine ring to which it is fused and that are components of the penicillin mixture or are produced biosynthetically by the use of different strains of molds or different media or are synthesized chemically

3

: a salt or ester of a penicillin acid or a mixture of such salts or esters