necessity

noun

ne·​ces·​si·​ty ni-ˈse-sə-tē 

-ˈse-stē

plural necessities

1

: the quality or state of being necessary

He questioned the necessity for the change.

2

a

: pressure of circumstance

The plane was compelled by necessity to change its course.

b

: physical or moral compulsion

did it, not because he wanted to, but by necessity

c

: impossibility of a contrary order or condition

submitting to the necessity imposed by the physical laws of the universe

3

: the quality or state of being in need

especially : poverty

had come to help them in their necessity

4

a

: something that is necessary : requirement

Many families could not afford the bare necessities of life.

b

: an urgent need or desire

When his father collapsed, an ambulance became a necessity.

see also:

of necessity

Synonyms of necessity

• requirement
• must

Examples of necessity in a Sentence

Sunscreen is an absolute necessity for the beach.

food, clothes, and other basic necessities

Getting plenty of rest is a necessity.

Without a car, living close to work is a necessity.

All we took with us on our hiking trip were the bare necessities.

Recent Examples on the Web

What once felt like an opportunity to close has become something closer to a necessity. —Mike Bianchi, The Orlando Sentinel, 30 Apr. 2026

Demineralization filters Most humidifiers today are filterless, as many consumers find the necessity of changing one aggravating. —Bestreviews, Mercury News, 30 Apr. 2026

Lithium was included on the 2025 List of Critical Minerals because of its necessity in batteries for computers, military equipment, vehicles, and energy-grid storage. —Aman Tripathi, Interesting Engineering, 30 Apr. 2026

However, the National Harbor area is already developed with necessities, including roads, water and sewer. —Jt Moodee Lockman, CBS News, 30 Apr. 2026

Word History

Etymology

Middle English necessite, from Anglo-French necessité, from Latin necessitat-, necessitas, from necesse

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing necessity

• born of necessity
• by necessity
• make a virtue of necessity
• make a virtue out of necessity
• necessity is the mother of invention
• necessity of life
• of necessity
• out of necessity

Kids Definition

necessity

noun

ne·​ces·​si·​ty ni-ˈses-ət-ē 

-ˈses-tē

plural necessities

1

: conditions that cannot be changed

forced by necessity

2

: the quality or state of being in need : poverty

3

a

: something that is necessary : requirement

the necessities for camping in comfort

b

: an urgent need or desire

call in case of necessity

Legal Definition

necessity

noun

ne·​ces·​si·​ty

plural necessities

1

a

: the presence or pressure of circumstances that justify or compel a certain course of action

especially : a need to respond or react to a dangerous situation by committing a criminal act

b

: an affirmative defense originating in common law that the defendant had to commit a criminal act because of the pressure of a situation that threatened a harm greater than that resulting from the act see also choice of evils defense at defense sense 2a compare duress, undue influence

2

: something that is necessary especially to subsistence

obligated to provide the necessities of food, clothing, and shelter