epidemic

1 of 2

adjective

ep·​i·​dem·​ic ˌe-pə-ˈde-mik 

1

: affecting or tending to affect a disproportionately large number of individuals within a population, community, or region at the same time

The outbreak of typhoid was epidemic.

2

a

: excessively prevalent

b

: contagious sense 4

epidemic laughter

3

: characterized by very widespread growth or extent : of, relating to, or constituting an epidemic

the practice had reached epidemic proportions

epidemical

ˌe-pə-ˈde-mi-kəl 

adjective

epidemically

ˌe-pə-ˈde-mi-k(ə-)lē 

adverb

epidemicity

ˌe-pə-də-ˈmi-sə-tē 

noun

epidemic

2 of 2

noun

1

: an outbreak of disease that spreads quickly and affects many individuals at the same time : an outbreak of epidemic disease

2

: an outbreak or product of sudden rapid spread, growth, or development

an epidemic of bankruptcies

Usage of Endemic, Epidemic, and Pandemic

Epidemic, pandemic, and endemic make up a trio of terms describing various degrees of an infectious disease's spread. Epidemic refers to an outbreak of a disease that can't be stopped or slowed, and in which the disease is spreading rapidly to many people within a localized community or region (such as a single country). An epidemic that has gone international is referred to as a pandemic: the disease, once localized in scope, now starts to appear in other countries and even on other continents, typically infecting a large number of people in a short amount of time. If a disease lingers for a long time as an epidemic or a pandemic, it may eventually become endemic to an area. The word endemic describes a disease that persists at a consistent level within a region with fairly predictable rates of infection and spread, making it easier to prevent future outbreaks.

Synonyms of epidemic

Adjective

• infectious

Examples of epidemic in a Sentence

Adjective

Overuse injuries—particularly in the elbows and shoulders of young pitchers—are indeed becoming epidemic. Orthopedists often blame coaches and parents for failing to monitor how many pitches kids are throwing and for not giving them time to rest their arms. —Sara Corbett, New York Times Sports Magazine, June 2006

The dream of running off to live the good life in a postcard perfect town in the mountains or by the sea often reaches epidemic proportions near the end of summer. —John Rasmus, National Geographic, September 2004

Saturday Night Fever propelled disco fever to epidemic proportions: By 1978, 40 percent of all the music on Billboard's Hot 100 was disco. —Peter Braunstein, American Heritage, November 1999

the little girl's giggles were epidemic, and soon the entire gathering was laughing

Noun

Cosmetic surgery is now so prevalent that it could qualify as a national epidemic. —Toni Bentley, New York Times Book Review, 22 Oct. 2006

"Spim," as people are beginning to call unsolicited instant messages, is the latest installment in the growing epidemic of unwanted electronic ads and a further sign that unscrupulous online marketers will seek to take advantage of all of the Internet's communication tools, not limiting themselves to spam or pop-up ads. —David McGuire, WashingtonPost.com, 13 Nov. 2003

Whatever might have motivated Kennedy to put [Ian] Fleming on his list, from that point, Bond became an international obsession. When the first Bond film appeared in 1962—Dr. No—the obsession was a full-blown craze, a cultural epidemic. —Gerald Early, New Letters, 1999

Recent Examples on the Web

Adjective

From Breath To Burnout The early identification of imbalances caused by chronic stress resonates deeply in our current health climate, where burnout, emotional exhaustion and cognitive fatigue are silently epidemic. —Trisha Swift, Forbes.com, 28 July 2025

But some researchers say the response should not be limited to the epidemic hot spots in big cities. —Byjon Cohen, science.org, 9 Dec. 2024

Noun

Most of humanity has fled into virtual reality to escape a world wracked by epidemics and climate change. —Carly Tagen-Dye, PEOPLE, 2 Nov. 2025

But the solution to the overreaction epidemic is emotion regulation—which will be vitally important to address our global challenges ahead. —Marc Brackett, Time, 28 Oct. 2025

Word History

Etymology

Adjective

borrowed from French épidémique, going back to Middle French, from epidemie "disease affecting a large number of individuals" + -ique -ic entry 1; Middle French epidemie, earlier epydimie, borrowed from Medieval Latin epidēmia, derivative (from feminine singular or neuter plural) of Late Latin epidēmius "widespread, prevalent (of a disease)," borrowed from Greek epidḗmios "within the country, among the people, prevalent (of a disease)," from epi- epi- + -dēmios, adjective derivative of dêmos "district, country, people" — more at demo-

Note: The notion that the word epidemic (adjective or noun) is owed directly to Hippocrates—or is, to put it more circumspectly, part of the Hippocratic Corpus—is somewhat illusory, a product of the words used in English translations. For example, in W. H. S. Jones' translation of De aere aquis et locis (Loeb Classical Library, 1923), the following passage (4.32-34) implies a distinction between "endemic" and "epidemic": "For men these diseases are endemic, besides there are epidemic diseases which may prevail through the change of the seasons." In the Greek text, however, "endemic diseases" are nosḗmata epichōría "illnesses of the country, native illnesses," while "epidemic diseases" translates ti pánkoinon, literally, "something common," i.e., "common or general diseases." Derivatives based on epi- and dêmos can be found in the Hippocratic texts (e.g., "Kaì gàr állōs tò nósēma epídēmon ên," Epidemics 1.14; "Tà mèn epidēmḗsanta nosḗmata taûta," Epidemics 3.3), though epídēmon means simply "common, prevalent," and epidēmḗsanta "having become prevalent." The title Epidḗmia, conventionally translated "Epidemics," for the works in the Hippocratic Corpus dealing with seasonal diseases and case histories, is presumably post-classical.

Noun

noun derivative of epidemic entry 1

First Known Use

Adjective

1603, in the meaning defined at sense 1

Noun

1630, in the meaning defined at sense 2

Phrases Containing epidemic

• epidemic curve
• inter-epidemic

Rhymes for epidemic

• academic
• epistemic
• hyperemic
• anaemic
• endemic
• glycemic
• pandemic
• polemic
• systemic
• chemic
• remic
• hypovolemic

Kids Definition

epidemic

1 of 2 adjective

ep·​i·​dem·​ic ˌep-ə-ˈdem-ik 

: spreading widely and affecting many individuals at one time

epidemic

2 of 2 noun

1

: an outbreak of epidemic disease

2

: a sudden rapidly spreading outbreak or growth

a crime epidemic

Etymology

Adjective

derived from Greek epidēmia "an epidemic, visit," from epidēmos "visiting, epidemic," from epi- "on, at" and dēmos "people, the masses" — related to democracy

Medical Definition

epidemic

1 of 2 adjective

ep·​i·​dem·​ic ˌep-ə-ˈdem-ik 

variants also epidemical

-i-kəl 

1

: affecting or tending to affect an atypically large number of individuals within a population, community, or region at the same time

typhoid was epidemic

compare endemic, sporadic sense 1

2

: of, relating to, or constituting an epidemic

coronary disease … has hit epidemic proportions

—Herbert Ratner

epidemically

-i-k(ə-)lē 

adverb

epidemic

2 of 2 noun

1

: an outbreak of epidemic disease

2

: a natural population (as of insects) suddenly and greatly enlarged