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.

---

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

---

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

---

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.

---

Other Word 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

Example Sentences

In one striking case, a ground squirrel bone from Olduvai Gorge in Tanzania, dated to about 1.8 million years ago, showed evidence of infection by the parasite that causes sleeping sickness in humans.

From Science Daily

A jury inquest which concluded on 8 October 2025 found the medical cause of death to be an "invasive streptococcus pyogenes infection following male circumcision".

From BBC

Complications can include bacterial infection of scabs, and much more rarely, a swelling of the brain known as encephalitis, lung inflammation known as pnemonitis, and stroke.

From BBC

Evolution repurposed ancient infections into essential parts of human biology, including the placenta and adaptive immunity.

From The Wall Street Journal

These rare cells generate all major types of blood and immune cells needed for oxygen transport and protection against infection.

From Science Daily

Related Words

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