noun (n)

• a texture without roughness; smooth to the touch(noun.attribute)

  Example:
  Admiring the slim smoothness of her thighs.
  Some artists prefer the smoothness of a board.
  

  Antonym:
  raggedness, roughness
  

  source: wordnet30
• powerful and effective language(noun.communication)

  Example:
  His oily smoothness concealed his guilt from the police.
  

  Synonym:
  eloquence, fluency
  

  source: wordnet30
• the quality of being bland and gracious or ingratiating in manner(noun.attribute)

  Synonym:
  blandness, suaveness, suavity
  

  source: wordnet30
• the quality of having a level and even surface(noun.attribute)

  Example:
  The water was a glassy smoothness.
  The weather system of the Pacific is determined by the uninterrupted smoothness of the ocean.
  

  source: wordnet30
• the quality of being free from errors or interruptions(noun.attribute)

  Example:
  The five-speed manual gearbox is smoothness personified.
  

  source: wordnet30
• Quality or state of being smooth.(noun)

  source: webster1913