noun (n)

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

  Antonym:
  slenderness, tenuity, thinness
  

  source: wordnet30
• indistinct articulation(noun.communication)

  Example:
  Judging from the thickness of his speech he had been drinking heavily.
  

  source: wordnet30
• used of a line or mark(noun.attribute)

  Synonym:
  heaviness
  

  source: wordnet30
• resistance to flow(noun.attribute)

  Antonym:
  thinness
  

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

  source: webster1913