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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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Garfield was shot before germ theory was widely accepted by doctors, who did not wash their hands or sanitize medical tools. Kelly Lawler, USA Today, 7 Nov. 2025 People didn't really know about germ theory in those days. Lee Habeeb, MSNBC Newsweek, 22 Oct. 2025 However, a clearer explanation of Kennedy's war on vaccines can be found in his rejection of germ theory. Eric Berger, ArsTechnica, 9 June 2025 Better sanitation and understanding of germ theory are part of the story, but one key factor that’s transformed American childhood over the past century is the widespread adoption of vaccines. Anna North, Vox, 7 Dec. 2018 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 29 Nov. 2025.

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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