germ theory

noun

: a theory in medicine: infections, contagious diseases, and various other conditions result from the action of microorganisms

Examples of germ theory in a Sentence

Recent Examples on the Web
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Acceptance of the germ theory of disease likely saved more lives than any other single development in the history of medicine. Literary Hub, 27 Mar. 2026 This idea—germ theory—wasn’t new, but no one had ever proven it. Encyclopedia Britannica, 20 Mar. 2026 Who’s to say the same pseudo-arguments won’t apply to life-saving cancer treatments, or to anesthesia, or to germ theory? Noubar Afeyan, Time, 9 Mar. 2026 Now, Jane Eyre is written before the advent of modern germ theory. David Frum, The Atlantic, 14 Jan. 2026 See All Example Sentences for germ theory

Word History

First Known Use

1863, in the meaning defined above

Time Traveler
The first known use of germ theory was in 1863

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Cite this Entry

“Germ theory.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/germ%20theory. Accessed 23 Apr. 2026.

Kids Definition

germ theory

noun
: the theory that infectious and contagious disease results from the action of living things

Medical Definition

germ theory

noun
: a theory in medicine: infections, contagious diseases, and various other conditions (as suppurative lesions) result from the action of microorganisms

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