noun (n)

• a quadrilateral with no parallel sides(noun.shape)

  Antonym:
  parallelogram
  

  source: wordnet30
• a multiple star in the constellation of Orion(noun.object)

  source: wordnet30
• the wrist bone on the thumb side of the hand that articulates with the 1st and 2nd metacarpals(noun.body)

  Synonym:
  os trapezium, trapezium bone
  

  source: wordnet30
• A plane figure bounded by four right lines, of which no two are parallel.(noun)

  source: webster1913