noun (n)

• the fullness of a tone of voice(noun.communication)

  Example:
  There is a musky roundness to his wordiness.
  

  Synonym:
  rotundity
  

  source: wordnet30
• the quality of being round numbers(noun.attribute)

  Example:
  He gave us the results in round numbers, but their roundness didn't affect the point he was making.
  

  source: wordnet30
• the property possessed by a line or surface that is curved and not angular(noun.attribute)

  Antonym:
  angularity
  

  source: wordnet30
• the bodily property of being well rounded(noun.attribute)

  Synonym:
  embonpoint, plumpness
  

  source: wordnet30
• The quality or state of being round in shape; as, the roundness of the globe, of the orb of the sun, of a ball, of a bowl, a column, etc.(noun)

  source: webster1913