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

Erin stresses the necessity of experiencing the mountains on their own terms, while Benji is adamant that the Alps have far more on tap than big, steep lines. —Sergei Poljak, Outside, 7 Mar. 2026

Mostly out of necessity, Ukraine developed cheap interceptor drones known as the Sting system, which are operated by pilots who can guide them to crash into Shahed drones, forcing them to explode. —Rebecca Schneid, Time, 7 Mar. 2026

And pitching successfully through in-game velocity declines is going to be a necessity. —Evan Grant, Dallas Morning News, 7 Mar. 2026

The researchers attribute that lag to existing legal constraints and technical hurdles such as model limitations, the necessity of additional software tools, and the need for humans to still review AI’s work. —Jake Angelo, Fortune, 6 Mar. 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