infirmity

noun

in·​fir·​mi·​ty in-ˈfər-mə-tē 

plural infirmities

1

a

: the quality or state of being infirm

b

: the condition of being feeble : frailty

2

: disease, malady

3

: a personal failing : foible

One of the besetting infirmities of living creatures is egotism.

—A. J. Toynbee

Synonyms of infirmity

• disease
• illness
• ailment
• ill
• sickness
• condition

Examples of infirmity in a Sentence

In recent years she has had to reduce her schedule because of age and infirmity.

the infirmities of old age

Recent Examples on the Web

Those are the words Dr. James Parkinson used in an essay more than 200 years ago to group together symptoms and describe a mysterious infirmity afflicting six individuals in London. —Andrea Kane, CNN Money, 9 Dec. 2025

Their income is limited, because of age or infirmity. —Dan Horn, Cincinnati Enquirer, 10 Nov. 2025

As if my sudden turn to sedentariness were the result of indolence, not infirmity. —Lucinda Rosenfeld, New Yorker, 25 Oct. 2025

Humor savors an infirmity — a foible, a failing, a venality, a flaw. —Big Think, 23 Sep. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1a

Kids Definition

infirmity

noun

in·​fir·​mi·​ty in-ˈfər-mət-ē 

plural infirmities

1

: the quality or state of being infirm

2

: ailment, disease

Medical Definition

infirmity

noun

in·​fir·​mi·​ty in-ˈfər-mət-ē 

plural infirmities

: the quality or state of being infirm

especially : an unsound, unhealthy, or debilitated state