pathogen

noun

path·​o·​gen ˈpa-thə-jən 

: a specific causative agent (such as a bacterium or virus) of disease

Examples of pathogen in a Sentence

Recent Examples on the Web

And the planet continues to warm, allowing these pathogens to spread to more and more farms all over the world, including in the US. — Dylan Scott, Vox, 27 Aug. 2026

FoodNet, short for the Foodborne Diseases Active Surveillance Network, was no longer required to actively report on six of eight pathogens, including Cyclospora, as of 2025. — Rebecca Schneid, Time, 26 Aug. 2026

Negative samples do not indicate that no pathogen is or was present in the case of cyclospora, as previously reported by USA TODAY. — Mary Walrath-Holdridge, USA Today, 26 Aug. 2026

Only later did doctors realize that the genetic material had probably come from a mushroom that the patient had consumed, and not from a pathogen. — Jason Liebowitz, New Yorker, 25 Aug. 2026

Word History

Etymology

patho- + -gen, after pathogenic, pathogenesis

First Known Use

1880, in the meaning defined above

Kids Definition

pathogen

noun

patho·​gen

ˈpath-ə-jən

: a germ (as a bacterium or virus) that causes disease

Medical Definition

pathogen

noun

patho·​gen ˈpath-ə-jən 

: a specific causative agent (as a bacterium or virus) of disease