[ dih-zeezd ]
/ dɪˈzizd /


having or affected with disease.

Origin of diseased

1425–75; late Middle English disesed; compare Anglo-French diseasé. See disease, -ed2

Related forms

non·dis·eased, adjectiveun·dis·eased, adjective

Can be confused

deceased diseased

Definition for diseased (2 of 2)


[ dih-zeez ]
/ dɪˈziz /


a disordered or incorrectly functioning organ, part, structure, or system of the body resulting from the effect of genetic or developmental errors, infection, poisons, nutritional deficiency or imbalance, toxicity, or unfavorable environmental factors; illness; sickness; ailment.
any abnormal condition in a plant that interferes with its vital physiological processes, caused by pathogenic microorganisms, parasites, unfavorable environmental, genetic, or nutritional factors, etc.
any harmful, depraved, or morbid condition, as of the mind or society: His fascination with executions is a disease.
decomposition of a material under special circumstances: tin disease.

verb (used with object), dis·eased, dis·eas·ing.

to affect with disease; make ill.

Origin of disease

1300–50; Middle English disese < Anglo-French dese(a)se, disaise; see dis-1, ease

Related forms

dis·eas·ed·ly, adverbdis·eas·ed·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diseased

British Dictionary definitions for diseased (1 of 2)


/ (dɪˈziːzd) /


having or affected with disease

British Dictionary definitions for diseased (2 of 2)


/ (dɪˈziːz) /


any impairment of normal physiological function affecting all or part of an organism, esp a specific pathological change caused by infection, stress, etc, producing characteristic symptoms; illness or sickness in general
a corresponding condition in plants
any situation or condition likened to thisthe disease of materialism

Related forms

Related adjective: pathological

Word Origin for disease

C14: from Old French desaise; see dis- 1, ease
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for diseased (1 of 2)


[ dĭ-zēzd ]


Affected with disease.
Unsound or disordered.

Medicine definitions for diseased (2 of 2)


[ dĭ-zēz ]


A pathological condition of a body part, an organ, or a system resulting from various causes, such as infection, genetic defect, or environmental stress, and characterized by an identifiable group of signs or symptoms.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.