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contagious

adjective
con·​ta·​gious | \ kən-ˈtā-jəs How to pronounce contagious (audio) \

Definition of contagious

1 : transmissible by direct or indirect contact with an infected person contagious diseases
2 : bearing contagion contagious people
3 : used for contagious diseases a contagious ward
4 : exciting similar emotions or conduct in others contagious enthusiasm contagious laughter
Other Words from contagious Synonyms & Antonyms What is the Difference Between contagious and infectious? More Example Sentences Learn More about contagious

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Other Words from contagious

contagiously adverb
contagiousness noun

What is the Difference Between contagious and infectious?

The words contagious and infectious can be confusing because they do not designate wholly distinct categories; something is not either contagious or infectious.

Essentially, infectious diseases and contagious diseases are caused by disease-producing agents such as bacteria and viruses, but they differ in that contagious diseases can be spread to other people by direct or indirect contact.

Anything contagious, such as the flu, is always automatically infectious: if you can catch it from someone, it's being passed to you via an infectious agent, which is the thing that gets you sick—usually a virus or a bacteria.

The reverse, however, isn't true. Just because something is infectious does not mean it's contagious. Food poisoning, for example, is infectious but not contagious: food can be contaminated with a bacteria (an infectious agent) that makes you sick, but you can't give your food poisoning to someone else by shaking their hand or even giving them a kiss.

Both contagious and infectious are also used figuratively, often in much happier contexts: laughter can be contagious; someone's enthusiasm can be infectious. While both words are used figuratively of both pleasant and unpleasant things, contagious is more often chosen for the unpleasant, as when it's grumpiness or fear that seems to be spreading.

Examples of contagious in a Sentence

It's a highly contagious virus. I have a cold and I'm still contagious. I'm sick, but the doctor says I'm not contagious.
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Recent Examples on the Web

 Twins Mark and Marcus Carter have the numbers growing, and the intensity contagious as program's rebuilding blocks get bigger. — Richard Obert, azcentral, "Arizona high school football: Previewing regions 5A Metro, 5A Northeast Valley," 11 Aug. 2019 Pam was a kind and generous woman with a sharp wit and contagious sense of humor. — sun-sentinel.com, "Deaths in South Florida: 8/11," 11 Aug. 2019 The show’s change in location from Los Angeles to Vegas could have heralded new creative energy for GLOW, transplanted into a city of windowless casino floors, bottomless well-liquor pours, and contagious desperation. — Sophie Gilbert, The Atlantic, "GLOW Goes Post-plot," 8 Aug. 2019 Gunn said the park cannot relocate the animals outside the park because of concerns about the transmission of Johne’s disease, a contagious ailment that has been detected in members of the herd. — Peter Fimrite, SFChronicle.com, "New Point Reyes management plan riles up environmentalists — comment sought," 8 Aug. 2019 He will be remembered by all who knew him as an outgoing, yet humble man, whose vibrant smile, deep voice and contagious laughter could light up any room. — courant.com, "Nathan Clark Faustin," 4 Aug. 2019 Murchison is perhaps better known for her work investigating a different contagious cancer that nearly crashed the world’s population of Tasmanian devils. — Megan Molteni, WIRED, "How a 6,000-Year-Old Dog Cancer Spread Around the World," 1 Aug. 2019 Thankfully, Moullec exudes a contagious confidence. — Robin Aigner, Condé Nast Traveler, "A Man, a Tiny Aircraft, and a Flock of Geese: Flying Among Birds in France," 22 July 2019 What this means for goats The key, Baciadonna says, is to next try to determine if emotions are contagious in any way. — Natasha Daly, National Geographic, "Goats can perceive each other’s emotions from their voices," 15 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'contagious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of contagious

14th century, in the meaning defined at sense 1

History and Etymology for contagious

see contagion

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More Definitions for contagious

contagious

adjective
How to pronounce contagious (audio)

English Language Learners Definition of contagious

: able to be passed from one person or animal to another by touching
: having a sickness that can be passed to someone else by touching
: capable of being easily spread to others : causing other people to feel or act a similar way

See the full definition for contagious in the English Language Learners Dictionary

contagious

adjective
con·​ta·​gious | \ kən-ˈtā-jəs How to pronounce contagious (audio) \

Kids Definition of contagious

1 : able to be passed from one individual to another through contact a contagious disease
2 : having a sickness that can be passed to someone else
3 : causing other people to feel or act a similar way a contagious laugh

contagious

adjective
con·​ta·​gious | \ -jəs How to pronounce contagious (audio) \

Medical Definition of contagious

1 : communicable by contact tuberculosis in the contagious stage
2 : bearing contagion many persons…are contagious long before they are aware of the presence of their disease — Journal of the American Medical Association
3 : used for contagious diseases a contagious ward

Other Words from contagious

contagiously adverb

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