noun (n)

• a principle that limits the extent of something(noun.cognition)

  Example:
  I am willing to accept certain restrictions on my movements.
  

  Synonym:
  limitation
  

  source: wordnet30
• an act of limiting or restricting (as by regulation)(noun.act)

  source: wordnet30
• the act of keeping something within specified bounds (by force if necessary)(noun.act)

  Example:
  The restriction of the infection to a focal area.
  

  Synonym:
  confinement
  

  source: wordnet30
• The act of restricting, or state of being restricted; confinement within limits or bounds.(noun)

  source: webster1913