infection

American  

[in-fek-shuhn] / ɪnˈfɛk ʃən /

noun

1. an act or fact of infecting; state of being infected.

2. an infecting with germs of disease, as through the medium of infected insects, air, water, or clothing.

3. an infecting agency or influence.

4. an infectious disease.

   Is this infection very dangerous?

5. the condition of suffering an infection.

6. corruption of another's opinions, beliefs, moral principles, etc.; moral contamination.

7. an influence or impulse passing from one to another and affecting feeling or action.

8. Grammar. (in Celtic languages) assimilation in which a vowel is influenced by a following vowel or semivowel; umlaut.

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infection British  

/ ɪnˈfɛkʃən /

noun

1. invasion of the body by pathogenic microorganisms

2. the resulting condition in the tissues

3. an infectious disease

4. the act of infecting or state of being infected

5. an agent or influence that infects

6. persuasion or corruption, as by ideas, perverse influences, etc

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infection Scientific  

/ ĭn-fĕk′shən /

1. The invasion of the body of a human or an animal by a pathogen such as a bacterium, fungus, or virus. Infections can be localized, as in pharyngitis, or widespread as in sepsis, and are often accompanied by fever and an increased number of white blood cells. Individuals with immunodeficiency syndromes are predisposed to certain infections.

2. See also infectious disease opportunistic infection

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infection Cultural  

1. Invasion of the body or a body part by a pathogenic organism, which multiplies and produces harmful effects on the body's tissues.

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Other Word Forms

Derived Forms

• noninfection
  noun
• postinfection
  adjective
• preinfection
  noun
• reinfection
  noun
• subinfection
  noun

Etymology

Origin of infection

1350–1400; Middle English infeccio ( u ) n < Late Latin infectiōn- (stem of infectiō ). See infect, -ion

Explanation

Infections are what happens when germs invade your body and cause a disease. Some, like meningitis, an infection of the tissues covering the brain and spinal cord, can be deadly. Others, like the common cold, are relatively mild. If you've ever scraped your knee and ended up with a swollen, achy scab, you know that you can develop an infection if you don't tend to your cuts and wounds and keep them clean. Though the word was traditionally used in the medical sense to refer to the pathogens, or germs, that cause illness, infection is now sometimes used in a broader sense to refer to people or things that act like pathogens. If rival gangs turn a neighborhood into a battleground, you could refer to this as an infection of gang activity.

Example Sentences

They’re ubiquitous across the Western world — an architectural infection spurred by capitalism’ need for generic efficiency borne of economies of scale.

From Salon • Jun. 8, 2026

Rivera's death was announced May 31 by the Nicaraguan health ministry, which said his health failed because of a bacterial infection caused by the Covid-19 virus.

From Barron's • Jun. 8, 2026

This organism can cause a rare but extremely deadly brain infection when contaminated water enters the nose, often during swimming or other recreational water activities.

From Science Daily • Jun. 6, 2026

To treat a screwworm infection, DeNotta said, people undergo the same combination of wound debridement and insecticides used in animals.

From Los Angeles Times • Jun. 6, 2026

His lung infection worsened, and he coughed up pus and mucous in fits that exhausted him.

From "Ambushed!" by Gail Jarrow

Related Words

• bug
• disease
• epidemic
• flu
• pollution
• virus