'Thickness' definitions:

Definition of 'thickness'

From: WordNet
noun
The dimension through an object as opposed to its length or width [ant: slenderness, tenuity, thinness]
noun
Indistinct articulation; "judging from the thickness of his speech he had been drinking heavily"
noun
Used of a line or mark [syn: thickness, heaviness]
noun
Resistance to flow [ant: thinness]

Definition of 'Thickness'

From: GCIDE
  • Thickness \Thick"ness\, n. [AS. ?icnes.] The quality or state of being thick (in any of the senses of the adjective). [1913 Webster]