What does penicillin mean?
Penicillin is an antibiotic medicine used to treat infections caused by susceptible bacteria. It belongs to the beta-lactam group and works by disrupting bacterial cell-wall formation, generally preventing the bacteria from multiplying. Penicillin was the first antibiotic discovered and developed for widespread medical use, and its introduction transformed the treatment of bacterial infections during the twentieth century. The term can refer either to penicillin medicines collectively or, more broadly, to related antibiotics known as penicillins. It has no effect against viruses, so it cannot be used to treat illnesses such as colds or influenza. Although modern medicine includes many penicillin derivatives designed to overcome resistance or broaden treatment options, the original medicine remains an important part of pharmacology. The word is also widely associated with allergy testing, since some people react adversely to penicillin and related medicines.
nounPenicillin is an antibiotic medicine, or a member of a group of related antibiotics, that acts by interfering with the growth of susceptible bacteria. It is used to treat certain bacterial infections but does not work against viruses.
- An antibiotic originally obtained from moulds of the genus Penicillium and used to treat susceptible bacterial infections.
- Any of a group of related beta-lactam antibiotics, including natural and semi-synthetic forms, that interfere with bacterial cell-wall formation.
"The doctor prescribed penicillin after the test confirmed a susceptible bacterial infection."
"She developed a penicillin allergy during childhood."
"The laboratory identified the organism as susceptible to penicillin."
The plural is used mainly to refer collectively to the class of related beta-lactam antibiotics, including natural and semi-synthetic forms. For an individual medicine, writers usually use the singular “penicillin” without a determiner or numeral.
"Newer penicillins are often prescribed when the infecting organism is resistant to standard penicillin."
Penicillin grew from Alexander Fleming's accidental observation that a mould had killed the surrounding bacteria, an observation that helped launch the antibiotic era.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of penicillin
The name was formed from the genus name Penicillium, which refers to the brush-like appearance of the mould's spores. Penicillium comes from the Latin penicillus, meaning “paintbrush” or “small brush,” a diminutive associated with penicillate forms. The compound was coined during the early development of antibiotic medicine, following Alexander Fleming's discovery of the antibacterial mould.
Related word forms
How penicillin is actually used
When naming a particular medicine, “penicillin” is commonly used without an article or numeral, as in “He was given penicillin.” The plural “penicillins” more often refers to the broader class of related antibiotics.