noun (n)

• the act of using(noun.act)

  Synonym:
  employment, exercise, use, utilisation, utilization
  

  source: wordnet30
• accepted or habitual practice(noun.act)

  Synonym:
  custom, usance
  

  source: wordnet30
• the customary manner in which a language (or a form of a language) is spoken or written(noun.communication)

  Example:
  English usage.
  A usage borrowed from French.
  

  source: wordnet30
• The act of using; mode of using or treating; treatment; conduct with respect to a person or a thing; as, good usage; ill usage; hard usage.(noun)

  source: webster1913