[uncountable] the fact that something must happen or be done; the need for something. necessity for something We recognize the necessity for a written ...

a thing that you must have and cannot manage without. Many people cannot even afford basic necessities such as food and clothing.

There are 19 meanings listed in OED's entry for the noun necessity, eight of which are labelled obsolete. See 'Meaning & use' for definitions, usage, ...

A good or service whose consumption by an individual, at a given price, rises less than in proportion to increases in their income.

1necessary (for somebody/something) (to do something) that is needed for a purpose or a reason synonym essential It may be necessary to buy a new one.

necessary · ​. that is needed for a purpose or a reason synonym essential. necessary to do something It may be necessary to buy a new one. · ​. [only before noun] ...

There are two meanings listed in OED's entry for the verb necessity. See 'Meaning & use' for definitions, usage, and quotation evidence. This word is now ...

to make something necessary; necessitate something; Recent financial scandals have necessitated changes in agency procedures.

In criminal law, a defence to any offence except murder. The defence can be raised only in cases of extraordinary duress (great or very sudden threat or ...

​to make something necessary. necessitate something Recent financial scandals have necessitated changes in parliamentary procedures. necessitate doing ...