Definition of "epidemic" in English

noun

1. A widespread disease that affects many humans in a population.

2. (epidemiology) An occurrence of a disease or disorder in a human population at a frequency higher than that expected in a given time period; an episode of outbreak and subsequent high prevalence.

3. (by extension, colloquial) A heightened occurrence of anything harmful.

4. (figurative) The spreading of an idea or belief amongst a population.

adjective

1. Of, related to, or being an epidemic: a widespread outbreak of disease in humans.

2. (figurative) Like an epidemic: widespread in a bad way.

   • Epidemic hysteria occurred upon the incumbent’s reelection.