epidemic

American  

[ep-i-dem-ik] / ˌɛp ɪˈdɛm ɪk /

adjective

1. Also epidemical (of a disease) affecting many persons at the same time, and spreading from person to person in a locality where the disease is not permanently prevalent.

2. extremely prevalent; widespread.

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noun

1. a temporary prevalence of a disease.

2. a rapid spread or increase in the occurrence of something.

   an epidemic of riots.

epidemic British  

/ ˌɛpɪˈdɛmɪk /

adjective

1. (esp of a disease) attacking or affecting many persons simultaneously in a community or area

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noun

1. a widespread occurrence of a disease

   an influenza epidemic

2. a rapid development, spread, or growth of something, esp something unpleasant

   an epidemic of strikes

epidemic Scientific  

/ ĕp′ĭ-dĕm′ĭk /

1. An outbreak of a disease or illness that spreads rapidly among individuals in an area or population at the same time.

2. See also endemic pandemic

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epidemic Cultural  

1. A contagious disease that spreads rapidly and widely among the population in an area. Immunization and quarantine are two of the methods used to control an epidemic.

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Other Word Forms

• epidemically
  adverb
• epidemicity
  noun
• interepidemic
  adjective
• preepidemic
  noun

Etymology

Origin of epidemic

First recorded in 1595–1605; obsolete epidem(y) (from Late Latin epidēmia, from Greek epidēmía “staying in one place, among the people,” equivalent to epi- epi- + dêm(os) “people of a district” + -ia -y ³ ) + -ic

Explanation

An epidemic is a disease that spreads rapidly among many people in a community at the same time. In the 1980s, the fast-spreading AIDS epidemic transformed life on our planet. Epidemic can be used figuratively to refer to something that spreads or grows rapidly: an epidemic of laziness has taken over the tenth grade. This word is from French épidémique, ultimately from Greek epidēmia "staying in one place, among the people." The related word pandemic refers to a disease that spreads throughout an entire country or throughout the world.

Example Sentences

There is no vaccine or treatment for Bundibugyo, the Ebola strain behind the current epidemic, and the odds of surviving an infection are as low as 50%.

From The Wall Street Journal • May 24, 2026

In the space of several weeks, the outbreak has spread to several provinces nearby and on to Ugandan soil, with the World Health Organization declaring the epidemic an international emergency.

From Barron's • May 24, 2026

“I was surprised to see so many people talking not just about the situation that Jeremy’s in, but an epidemic that small businesses are facing,” Newman said.

From Los Angeles Times • May 21, 2026

One silver linings of the 2014 Ebola epidemic was that it accelerated vaccine development, resulting in the Ervebo vaccine, which is 97.5% effective at preventing infection and has been used to contain subsequent outbreaks.

From Salon • May 20, 2026

While the New World and Australia did not harbor native epidemic diseases awaiting Europeans, tropical Asia, Africa, Indonesia, and New Guinea certainly did.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Related Words

• contagion
• outbreak
• pest
• plague
• rash
• scourge
• spread
• wave