addition vs necessity

addition

noun
  • The act of adding anything. 

  • The arithmetic operation of adding. 

  • A dot at the right side of a note as an indication that its sound is to be lengthened one half. 

  • Anything that is added. 

  • A title annexed to a person's name to identify him or her more precisely. 

  • Something added to a coat of arms, as a mark of honour. 

necessity

noun
  • 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. 

  • Something necessary; a requisite; something indispensable. 

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

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