Definition of "familiarity"

familiarity

/fəmɪliˈæɹɪti/

noun
countable and uncountable, plural familiarities
1. The state of being extremely friendly; intimacy.
  Quotations
  It is also folly and injustice to deprive children […] of their fathers familiaritie, and ever to shew them a surly, austere, grim, and disdainefull countenance, hoping thereby to keepe them in awfull feare and duteous obedience.
  1603, Michel de Montaigne, chapter 8, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […]
  Do not keep familiarity with any but those, with whom you may improve your time.
  1677, Hannah Woolley, The Compleat Servant-Maid‎, London: T. Passinger, page 2
2. Undue intimacy; inappropriate informality, impertinence.
  Quotations
  Murrel did not in the least object to being called a monkey, yet he always felt a slight distaste when Julian Archer called him one. […] It had to do with a fine shade between familiarity and intimacy which men like Murrel are never ready to disregard, however ready they may be to black their faces.
  1927, G K Chesterton, The Return of Don Quixote, page 5
3. An instance of familiar behaviour.
4. Close or habitual acquaintance with someone or something; understanding or recognition acquired from experience.
  Quotations
  The objects around have been seen so often, that they have at last become, as it were, unseen; their familiarity does not carry us out of ourselves, for all their associations are our own.
  1837, L[etitia] E[lizabeth] L[andon], “The Influence of the Dead”, in Ethel Churchill: Or, The Two Brides. […], volume II, London: Henry Colburn, […], page 269