noun (n)

• relatively small dimension through an object as opposed to its length or width(noun.attribute)

  Example:
  The thinness of a rope.
  

  Synonym:
  slenderness, tenuity
  

  source: wordnet30
• the property of having little body fat(noun.attribute)

  Synonym:
  leanness, spareness
  Antonym:
  avoirdupois, blubber, fat, fatness
  

  source: wordnet30
• the property of being very narrow or thin(noun.attribute)

  Synonym:
  fineness
  

  source: wordnet30
• the property of being scanty or scattered; lacking denseness(noun.attribute)

  Synonym:
  spareness, sparseness, sparsity
  

  source: wordnet30
• a consistency of low viscosity(noun.attribute)

  Example:
  He disliked the thinness of the soup.
  

  Antonym:
  thickness
  

  source: wordnet30
• The quality or state of being thin (in any of the senses of the word).(noun)

  source: webster1913