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

Considering the outsize roll these pathogens play in driving severe respiratory illnesses, such as pneumonia, these pauses are alarming. — John Kubale, The Conversation, 8 July 2026

Last May, the president issued an executive order meant to limit and track all research that involves the potential enhancement of dangerous pathogens. — Daniel Engber, The Atlantic, 7 July 2026

The United States has comparatively fewer pesky pathogens to worry about 250 years later (measles resurgence, notwithstanding). — Helen Branswell, STAT, 6 July 2026

Jamestown Canyon virus may not be an emerging pathogen in the usual sense. — John Drake, Forbes.com, 4 July 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