noun (n)

• a travelling company of entertainers; including trained animals(noun.group)

  Example:
  He ran away from home to join the circus.
  

  source: wordnet30
• a performance given by a traveling company of acrobats, clowns, and trained animals(noun.act)

  Example:
  The children always love to go to the circus.
  

  source: wordnet30
• a frenetic disorganized (and often comic) disturbance suggestive of a large public entertainment(noun.act)

  Example:
  It was so funny it was a circus.
  

  Synonym:
  carnival
  

  source: wordnet30
• (antiquity) an open-air stadium for chariot races and gladiatorial games(noun.artifact)

  source: wordnet30
• an arena consisting of an oval or circular area enclosed by tiers of seats and usually covered by a tent(noun.artifact)

  Example:
  They used the elephants to help put up the circus.
  

  source: wordnet30
• a genus of haws comprising the harriers(noun.animal)

  Synonym:
  genus circus
  

  source: wordnet30
• A level oblong space surrounded on three sides by seats of wood, earth, or stone, rising in tiers one above another, and divided lengthwise through the middle by a barrier around which the track or course was laid out. It was used for chariot races, games, and public shows.(noun)

  source: webster1913