necessity

Definitions

General English

Aviation

  • noun something that is necessary or very important

Commerce

  • noun something which is vitally important, without which nothing can be done or no one can survive

Economics

  • noun a thing which is vitally important, without which nothing can be done or a person cannot survive

Health Economics

  • (written as Necessity)
    Economists frown on loaded terms like luxury and necessity and they generally have no precise meaning in economics. Of course, this has not stopped them being used.
http://www.dictionarycentral.com/definition/necessity.html