pathogen
Americannoun
noun
-
An agent that causes infection or disease, especially a microorganism, such as a bacterium or protozoan, or a virus.
-
See Note at germ
Other Word Forms
Etymology
Origin of pathogen
Explanation
A pathogen is a tiny living organism, such as a bacterium or virus, that makes people sick. Washing your hands frequently helps you avoid the pathogens that can make you sick. Pathos is the Greek word for disease and -genes means "born of." So, a pathogen is something that causes disease, like a virus like the rhinovirus, which causes the common cold. At summer picnics, people are cautious about keeping certain foods like potato salad in coolers with ice — the eggs in such dishes spoil quickly out in the heat, introducing pathogens that can make people sick.
Vocabulary lists containing pathogen
Common Senses: Path ("Feeling")
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
This familiarity stands in stark contrast to SARS-CoV-2, a novel pathogen that wasn’t detected until 2019.
From Barron's • May 11, 2026
A more powerful approach, called shotgun sequencing, extracts genetic material from a patient’s samples and runs it through a machine that can flag an unknown pathogen.
From The Wall Street Journal • May 6, 2026
Few countries, he said, systematically track which species are being traded across their borders, and even fewer conduct routine pathogen screening in those animals.
From Los Angeles Times • Apr. 13, 2026
By combining genetic, archaeological, environmental, and pathogen data, the study reveals how ancient communities dealt with overlapping challenges such as climate instability, food stress, and disease.
From Science Daily • Mar. 21, 2026
The first is the lack of acquired immunity—immunity gained from a previous exposure to a pathogen.
From "1491" by Charles C. Mann
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
