diseased
Americanadjective
adjective
Other Word Forms
Etymology
Origin of diseased
1425–75; late Middle English disesed; compare Anglo-French diseasé. See disease, -ed 2
Explanation
When something is unhealthy or affected by illness, it's diseased. Sadly, the diseased trees in the city park may eventually need to be cut down and removed. While this adjective essentially means "sick," it's not generally used to describe people. Instead, you might use it for plants, animals, or body parts: "Hepatitis can result in a diseased liver." Diseased comes from the Old French desaise, "discomfort or sickness," from des-, "without," and aise, "ease."
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.
He is also concerned about unregulated nurseries selling unidentified, or diseased plants.
From BBC ● Sep. 4, 2026
Eventually, they hope to compare circulation patterns between healthy and diseased brains, as well as between younger and older brains.
From Science Daily ● Aug. 13, 2026
Professor of Molecular & Integrative Physiology, graduate student researcher Jessica Maung, Ph.D., and a broader collaborative team to investigate what happens inside diseased fat tissue.
From Science Daily ● Jul. 26, 2026
Wacky animal sidekicks once felt vibrant in a holistic world of artifice; here, a goggle-eyed rooster just looks diseased.
From Los Angeles Times ● Jul. 9, 2026
Not diseased skinny, just ugly skinny—she’d never eaten much.
From "Uglies" by Scott Westerfeld
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.
