demand vs necessity

demand

noun
  • A requirement. 

  • An urgent request. 

  • The desire to purchase goods and services. 

  • An order. 

  • The amount of a good or service that consumers are willing to buy at a particular price. 

  • A forceful claim for something. 

  • More precisely peak demand or peak load, a measure of the maximum power load of a utility's customer over a short period of time; the power load integrated over a specified time interval. 

verb
  • To require of someone. 

  • To claim a right to something. 

  • To ask forcefully for information. 

  • To request forcefully. 

  • To issue a summons to court. 

necessity

noun
  • Something necessary; a requisite; something indispensable. 

  • Something which makes an act or an event unavoidable; an irresistible force; overruling power. 

  • Greater utilitarian good; used in justification of a criminal act. 

  • Indispensable requirements (of life). 

  • The negation of freedom in voluntary action; the subjection of all phenomena, whether material or spiritual, to inevitable causation; necessitarianism. 

  • The condition of being needy; desperate need; lack. 

  • The quality or state of being necessary, unavoidable, or absolutely requisite. 

How often have the words demand and necessity occurred in a corpus of books? (source: Google Ngram Viewer )