necessity

American  

[nuh-ses-i-tee] / nəˈsɛs ɪ ti /

noun

plural

necessities

1. something necessary or indispensable.

   food, shelter, and other necessities of life.

2. the fact of being necessary or indispensable; indispensability.

   the necessity of adequate housing.

3. an imperative requirement or need for something.

   the necessity for a quick decision.

   Synonyms:

   demand

4. the state or fact of being necessary or inevitable.

   to face the necessity of testifying in court.

5. an unavoidable need or compulsion to do something.

   not by choice but by necessity.

6. a state of being in financial need; poverty.

   a family in dire necessity.

   Synonyms:

   want, indigence, neediness

7. Philosophy. the quality of following inevitably from logical, physical, or moral laws.

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idioms

1. of necessity, as an inevitable result; unavoidably; necessarily.

   Our trip to China must of necessity be postponed for a while.

necessity British  

/ nɪˈsɛsɪtɪ /

noun

1. (sometimes plural) something needed for a desired result; prerequisite

   necessities of life

2. a condition or set of circumstances, such as physical laws or social rules, that inevitably requires a certain result

   it is a matter of necessity to wear formal clothes when meeting the Queen

3. the state or quality of being obligatory or unavoidable

4. urgent requirement, as in an emergency or misfortune

   in time of necessity we must all work together

5. poverty or want

6. rare compulsion through laws of nature; fate

7. philosophy

   1. a condition, principle, or conclusion that cannot be otherwise

   2. the constraining force of physical determinants on all aspects of life Compare freedom

8. logic

   1. the property of being necessary

   2. a statement asserting that some property is essential or statement is necessarily true

   3. the operator that indicates that the expression it modifies is true in all possible worlds

9. inevitably; necessarily

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necessity More Idioms  

More idioms and phrases containing necessity

• make a virtue of necessity
• of necessity

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Related Words

See need.

Other Word Forms

• nonnecessity
  noun
• supernecessity
  noun

Etymology

Origin of necessity

First recorded in 1325–75; Middle English necessite, from Latin necessitās, from necess(e) “needful” + -itās -ity

Explanation

A good camping knife is a necessity if you’re going to be hiking in a heavily forested region. A necessity is something that you must have in order to complete a task. When used in the plural, necessities are items required for a situation but nothing extra. You probably only bring the bare necessities to a sleepover — pajamas and a toothbrush. Sometimes a necessity is a thing you must know how to do. Knowing how to balance your checkbook is a financial necessity. In some cases, necessity simply means "need." Do you do your homework out of necessity or because you want to?

Example Sentences

Necessity is the mother of invention, and this new wave of persecution will push the Chinese church toward greater dynamism even as it fights to survive—on or offline.

From The Wall Street Journal • Oct. 27, 2025

Necessity bred invention, and furniture and wood products makers found glues and binders with no added formaldehyde.

From Salon • Dec. 9, 2024

A travel-friendly set of daily essentials, the Necessity Kit includes mini versions of F. Miller’s bestselling products like its face and body oil, packaged in a reusable washed paper bag made from recycled content.

From Los Angeles Times • Nov. 27, 2024

Necessity being the mother of invention, we had no option but to think laterally.

From Scientific American • Aug. 18, 2023

Necessity, you might say, was the mother of invention.

From "Words Like Loaded Pistols" by Sam Leith

Related Words

• essential
• fundamental
• obligation
• precondition
• prerequisite
• requirement
• urgency