necessity

necessity — noun

1. a situation in which something is required to happen or exist because it is need

1.nounB2
Definition

a situation in which something is required to happen or exist because it is needed.

Example

Hoa emphasized the necessity of saving money for unexpected medical bills.

necessity of + gerund (pattern)

The growing necessity for clean energy has led to many new inventions.

necessity for + noun (pattern)

Common collocations
  • absolute necessity
  • dire necessity
  • economic necessity
  • out of necessity
  • by necessity
  • sheer necessity
  • necessity arises
  • of necessity
Synonyms
  • need

    broader and less formal; can express personal desire rather than objective requirement

  • requirement

    more formal, often used in official rules or conditions

  • demand

    suggests external pressure or a market-driven force rather than an internal need

  • prerequisite

    narrower; something that must exist before another thing can happen

Antonyms
  • option

    something that can be chosen or not, with no obligation

  • luxury

    something desirable but not essential

Grammar Patterns

necessity + for + noun

necessity + of + gerund

necessity + to-infinitive

Usage Note

Commonly followed by 'for' + noun phrase, 'of' + gerund, or a to-infinitive. In formal writing, 'necessity' carries stronger urgency than 'need' and is often used in contexts of rules, survival, or unavoidable situations.

Common Mistakes

I bought food out of necessary.
I bought food out of necessity.
'necessary' is an adjective; 'necessity' is the noun form.
There is necessity to leave now.
There is a necessity to leave now.
when used with a to-infinitive, 'necessity' usually requires the article 'a'.

2. a basic item such as food, water, or housing that a person must have to survive

2.nounB2
Definition

a basic item such as food, water, or housing that a person must have to survive and live normally.

Example

After months of drought, the villagers lined up for clean drinking water — it was a basic necessity.

basic necessity (common collocation)

After losing her job, Kemi could only afford the bare necessities like rice and soap.

bare necessities (common collocation)

Common collocations
  • basic necessity
  • bare necessities
  • daily necessities
  • household necessities
  • living necessities
Synonyms
  • essential

    more common in everyday speech; 'basic essentials' covers the same idea

  • requisite

    very formal; used mainly in technical or bureaucratic writing

  • staple

    narrower; refers mainly to basic food items such as rice, flour, or oil

Antonyms
  • luxury

    something pleasant to have but not required for survival

  • extravagance

    an expensive item that goes well beyond what is needed

Grammar Patterns

bare necessities

basic necessity

daily necessities

household necessities

Usage Note

Often used in the plural form 'necessities' when referring to basic living needs. The phrase 'bare necessities' refers to the absolute minimum items needed for survival.

Common Mistakes

Water is a necessary.
Water is a necessity.
'necessary' is an adjective; 'necessity' is the correct noun form.
She bought some necessity at the store.
She bought some necessities at the store.
when talking about basic living items, the plural form is more natural.
Idioms

make a virtue of necessity

idiom

To turn a situation you cannot avoid into something positive or useful.

Maya made a virtue of necessity by using the long wait to finish her book.

When the flight was cancelled, Diego made a virtue of necessity and explored the airport shops.

necessity is the mother of invention

idiom

Difficult situations cause people to create new solutions.

When the power went out, necessity was the mother of invention for Sara's candle holder.

Necessity is the mother of invention, so the broken bike led to a clever repair.

Word family

Synonym discussion

Sense: noun/1

While 'need' is the most general term for anything necessary or desired — and can express personal wants — 'necessity' carries stronger urgency and implies objective unavoidability. A 'requirement' is an official condition set by rules or authority (e.g., a visa requirement), whereas a 'necessity' is driven by the situation itself. 'Demand' shifts the focus to external pressure or quantity: market demand rises and falls. 'Prerequisite' is the narrowest: it names something that must be in place before something else can happen, like a prerequisite course. For example, 'Food is a basic necessity for survival' would sound odd with 'prerequisite' or 'demand'. And 'the necessity of regular exercise' suggests deeper compulsion than 'the need for regular exercise.'

need ↗requirement ↗demand ↗prerequisite ↗

Common collocations

Phrases

  • out of necessity
  • by necessity
  • of necessity

Prepositions

Etymology

LatinFrenchEnglish

The word 'necessity' came into English through Old French 'necessite', from Latin 'necessitas' meaning compulsion or need. The Latin root 'necesse' was formed from 'ne-' (not) and 'cedere' (to give way, to yield), giving the original sense of something that cannot be avoided or yielded to.