English to English

noun (n)

• a four-sided polygon(noun.shape)

  Synonym:
  quadrilateral, tetragon
  

  source: wordnet30
• a rectangular area surrounded on all sides by buildings(noun.artifact)

  Synonym:
  quad
  

  source: wordnet30
• A plane figure having four angles, and consequently four sides; any figure having four angles.(noun)

  source: webster1913