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noun B2 Upper-Intermediate

penicillin

pehn-ih-SIHL-ihn

Penicillin (noun) means an antibiotic medicine derived from Penicillium mold, used to treat bacterial infections. Example: “The doctor prescribed penicillin for his throat infection.”

noun
1
An antibiotic medicine derived from Penicillium mold, used to treat bacterial infections.
"The doctor prescribed penicillin for his throat infection."
"Some people have a serious allergic reaction to penicillin."

How to use penicillin

Learner’s notes

In plain EnglishA widely used antibiotic drug made from a type of mold.

Common mistake

Penicillin allergies are common and can be serious — always mention them to a doctor before treatment.

Common pairings
allergic to penicillin a course of penicillin

Word forms

penicillins plural

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Fill the gap

Can you complete this real example?

The doctor prescribed _____ for his throat infection.

Etymology

Named after the Penicillium mold from which it was first isolated; coined by Alexander Fleming, who discovered it in 1928.

· First attested 1928

Class of 1928 penicillin joined the language around 1928.
See the full Class of 1928 →

Rhymes for penicillin

See all rhymes for penicillin →

Frequently asked questions

What does “penicillin” mean?

The word “penicillin” means an antibiotic medicine derived from Penicillium mold, used to treat bacterial infections. In plain terms, a widely used antibiotic drug made from a type of mold.

How do you pronounce “penicillin”?

“Penicillin” is pronounced pehn-ih-SIHL-ihn (/ˌpɛn.ɪˈsɪl.ɪn/ in IPA).

How do you use “penicillin” in a sentence?

Here is “penicillin” used in a sentence: “The doctor prescribed penicillin for his throat infection.”

What part of speech is “penicillin”?

“Penicillin” is a noun.

Where does the word “penicillin” come from?

The word “penicillin” dates back to around 1928. Named after the Penicillium mold from which it was first isolated; coined by Alexander Fleming, who discovered it in 1928.

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