Definition of deleterious
: harmful often in a subtle or unexpected way deleterious effects deleterious to health
deleterious was our Word of the Day on 05/31/2011. Hear the podcast!
Examples of deleterious in a sentence
In developing countries, the imposition of boundaries around national parks and protected areas has been deleterious for both people and wildlife. —Kristin B. Gunther, Association of American Geographers, 2002
Most everyone now knows the action of pressing mouse keys is far more deleterious to the tender structures of the wrist and hand than typing is. —Michael Finley, Albany (New York) Times-Union, 2 Sept. 1998
This skewed allocation of resources away from those most in need, in turn, insures that many young people from low-income families will continue to be shut out of the economy, with obvious deleterious family and social consequences. —Iris C. Rotberg, Education Week, 9 Mar. 1994
For as James Keirans pointed out to me, ticks are the world's most notorious carriers of the agents of diseases that strike animals, wild and domestic. And they rank second only to mosquitoes in their deleterious effect on humans. —Edwards Park, Smithsonian, January 1987
The chemical is deleterious to the environment.
The drug has no deleterious effects on patients.
Origin and Etymology of deleterious
Greek dēlētērios, from dēleisthai to hurt
First Known Use: 1643
Synonym Discussion of deleterious
DELETERIOUS Defined for English Language Learners
Definition of deleterious for English Language Learners
: damaging or harmful
Medical Definition of deleterious
: harmful often in a subtle or an unexpected way the deleterious effects of radiation and chemotherapy on the marrow—Christine Gorman deleterious genes
Seen and Heard
What made you want to look up deleterious? Please tell us where you read or heard it (including the quote, if possible).