noun (n)

• great skillfulness and knowledge of some subject or activity(noun.cognition)

  Synonym:
  command, control
  

  source: wordnet30
• power to dominate or defeat(noun.state)

  Example:
  Mastery of the seas.
  

  Synonym:
  domination, supremacy
  

  source: wordnet30
• the act of mastering or subordinating someone(noun.act)

  Synonym:
  subordination
  

  source: wordnet30
• The position or authority of a master; dominion; command; supremacy; superiority.(noun)

  source: webster1913