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

Its crisis – along with those of other property giants – has been at the heart of a wider Chinese real-estate shock that has tested the world’s second-largest economy and threatened to spark a global contagion effect. — Sylvie Zhuang, CNN Money, 20 Aug. 2026

Many countries will benefit from similar hedgehog strategies that draw on the technological revolution favoring defense, insulating their territories against contagion. — Mark Leonard, Foreign Affairs, 18 Aug. 2026

The continued appearance of the virus’ telltale rash in state after state since last year warns of cracks in our once-solid protection, leaving communities vulnerable to other deadly contagions. — Patricia Callahan, ProPublica, 18 Aug. 2026

An emotional contagion like panic is always possible, but Vilhauer does not think most people would react that way even to such paradigm-shifting news as nonhuman intelligence. — Jeffrey Kluger, Time, 6 Aug. 2026

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)