infection
Americannoun
-
infections
plural
-
an infecting with germs of disease, as through the medium of infected insects, air, water, or clothing.
-
an infecting agency or influence.
-
an infectious disease.
Is this infection very dangerous?
-
the condition of suffering an infection.
-
corruption of another's opinions, beliefs, moral principles, etc.; moral contamination.
-
an influence or impulse passing from one to another and affecting feeling or action.
-
Grammar. (in Celtic languages) assimilation in which a vowel is influenced by a following vowel or semivowel; umlaut.
noun
-
invasion of the body by pathogenic microorganisms
-
the resulting condition in the tissues
-
an infectious disease
-
the act of infecting or state of being infected
-
an agent or influence that infects
-
persuasion or corruption, as by ideas, perverse influences, etc
-
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.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
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.
Vocabulary lists containing infection
“About Edward Jenner” from the Jenner Institute
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Life Science: Human Systems
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
National Nurses Week: Medical Branches and Conditions
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
"Obviously it can be a very severe infection," he said, but he warned against taking a course of antibiotics without known exposure.
From Barron's ● Oct. 8, 2026
It’s not wet with phlegm from a bronchial infection; the kind that makes seatmates on the plane jump for the Purell.
From Los Angeles Times ● Oct. 8, 2026
In June, a US plan to establish an Ebola treatment facility at a military base in the central Kenyan town of Nanyuki sparked concern, with Kenyans reacting furiously about the risks of cross-border infection.
From BBC ● Oct. 7, 2026
Since her infection, contacts of the woman have been put under medical observation.
From The Wall Street Journal ● Oct. 6, 2026
The president received antibiotics to fight possible infection and transfusions to replace his significant blood loss.
From "Ambushed!" by Gail Jarrow
Both Beni and Kasindi are in North Kivu, which has recorded 1,755 Ebola infections and more than 1,000 deaths, making it one of the Congolese provinces worst-hit by the disease.
From BBC ● Oct. 10, 2026
Pennsylvania’s infections surpassed the 997 recorded in a South Carolina outbreak that ended earlier this year.
From The Wall Street Journal ● Oct. 7, 2026
The agency also said the woman had been "vaccinated and had immunity to dangerous infections with which she worked".
From Barron's ● Oct. 7, 2026
This bacterial species has been linked to infections that can be difficult to treat.
From Science Daily ● Oct. 7, 2026
It will take nearly a century for science to develop the first "antibiotic," penicillin, to counter infections.
From "Phineas Gage" by John Fleischman
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
