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

Cyclosporiasis is an illness caused by a pathogen in tainted produce, which has already sickened thousands of Americans this summer. — Taylor Swinton, Washington Post, 17 July 2026

Bird feeders can attract rodents, which often serve as reservoirs for the pathogens that ticks pick up and can transmit to you. — Amanda Roome, The Conversation, 16 July 2026

Roaches can pose a health threat in your home, and have been linked to the spread of bacteria, parasitic worms and human pathogens. — Faith Wakefield, USA Today, 16 July 2026

Symptoms can include diarrhea, abdominal cramps, nausea and fatigue that overlap considerably with other gastrointestinal illnesses, making clinical diagnosis difficult without specific laboratory testing to identify the causative pathogen. — Marina Johnson, Louisville Courier Journal, 15 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