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.
Diseased kidneys release tiny particles known as "circulating extracellular vesicles" into the bloodstream.
From Science Daily • Jan. 20, 2026
Diseased pumpkins sometimes produce an off-putting smell, so use your nose as well.
From Scientific American • Oct. 19, 2022
Diseased ash trees which "effectively explode" while being cut down pose a serious risk to people's safety, forestry organisations have warned.
From BBC • Mar. 30, 2022
Diseased trees in Europe are considered an occupational hazard, suffered by people with intensive job-related contact with wood, such as mill workers.
From Seattle Times • Jul. 11, 2021
He did so immediately: in 1933, less than five months after the passage of the Enabling Act, the Nazis enacted the Law for the Prevention of Genetically Diseased Offspring—commonly known as the Sterilization Law.
From "The Gene" by Siddhartha Mukherjee
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.
