contagion

noun

con·​ta·​gion kən-ˈtā-jən 

1

a

: a contagious disease

b

: the transmission of a disease by direct or indirect contact

c

: a disease-producing agent (such as a virus)

2

a

: poison

b

: contagious influence, quality, or nature

c

: corrupting influence or contact

3

a

: rapid communication of an influence (such as a doctrine or emotional state)

b

: an influence that spreads rapidly

Examples of contagion in a Sentence

a disease that spreads by contagion

People have been warned to keep out of the area to avoid contagion.

Recent Examples on the Web

The Israeli intelligence assessments align with warnings from a senior foreign diplomatic source, who described the current threat environment as being driven by a global contagion effect, in which extremist networks worldwide amplify and celebrate attacks, encouraging others to replicate them. —Efrat Lachter, FOXNews.com, 15 Dec. 2025

For one, statistical modeling typically requires contagion to occur within a tight temporal window, often 1 to 3 years. —Jonathan Powell, The Conversation, 15 Dec. 2025

The lack of information surrounding outbreaks is a new and troubling trend among local and state officials nationwide, according to health advocates and lawyers who specialize in tracking foodborne illnesses and other environmental contagions. —Robert Anglen, AZCentral.com, 8 Dec. 2025

While the current study centered on behavior, Peng hopes to explore how internal states arise and move between individuals, including the neural pathways that might support contagion. —New Atlas, 7 Dec. 2025

Word History

Etymology

Middle English contagioun, borrowed from Anglo-French & Latin; Anglo-French contagiun, borrowed from Latin contāgiōn, contāgiō "contact, contact resulting in disease, infection, pollution," from contag-, variant stem of contingere "to be in contact with, arrive at, affect, fall to one's lot" + -iōn-, -iō, suffix of action nouns formed from compound verbs — more at contingent entry 1

Note: The vowel length in contāgiō is unexpected and difficult to explain; a similarly lengthened vowel is found in other deverbal derivatives with -ag- as a second member (compāgēs "bond, joint," from pangere, ambāgēs "circuitous path," from agere; see agent, pact).

First Known Use

14th century, in the meaning defined at sense 1a

Rhymes for contagion

• cajun

Kids Definition

contagion

noun

con·​ta·​gion kən-ˈtā-jən 

1

: the passing of a disease from one individual to another by direct or indirect contact

2

: a contagious disease or something (as a virus) that causes a contagious disease

Medical Definition

contagion

noun

con·​ta·​gion kən-ˈtā-jən 

1

: the transmission of a disease by direct or indirect contact

2

: contagious disease

3

: a disease-producing agent (as a virus)