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

Jernigan said those labs typically helped doctors identify pathogens using an online resource, or genetically sequence pathogens like Cyclospora to develop better treatments. — Yuki Noguchi, NPR, 20 Aug. 2026

From infancy onward interactions between intestinal microbes and immune cells help the body distinguish harmless microorganisms from disease-causing pathogens and regulate inflammatory responses. — Encyclopedia Britannica, 19 Aug. 2026

Though biological weapons are banned by international law, a handful of countries, including Russia, Syria, and North Korea, have developed and hoarded contagious pathogens. — The Week Us, TheWeek, 19 Aug. 2026

The ability to characterize and attribute threats, develop countermeasures, and respond rapidly to novel pathogens will depend heavily on the private sector, which needs to be not only a supplier but also an enduring national security partner. — Elizabeth Sherwood-Randall, Foreign Affairs, 18 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