noun (n)

• communication by the exchange of letters(noun.communication)

  source: wordnet30
• compatibility of observations(noun.attribute)

  Example:
  The results of two tests were in correspondence.
  

  Synonym:
  agreement
  

  source: wordnet30
• the relation of corresponding in degree or size or amount(noun.linkdef)

  Synonym:
  commensurateness, proportionateness
  

  source: wordnet30
• (mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane(noun.attribute)

  Synonym:
  balance, symmetricalness, symmetry
  Antonym:
  asymmetry, dissymmetry, imbalance
  

  source: wordnet30
• similarity by virtue of corresponding(noun.attribute)

  Synonym:
  parallelism
  

  source: wordnet30
• Friendly intercourse; reciprocal exchange of civilities; especially, intercourse between persons by means of letters.(noun)

  source: webster1913