'Tallness' definitions:

Definition of 'tallness'

(from WordNet)
noun
The vertical dimension of extension; distance from the base of something to the top [syn: height, tallness]
noun
The property of being taller than average stature [ant: shortness]

Definition of 'Tallness'

From: GCIDE
  • Tallness \Tall"ness\, n. The quality or state of being tall; height of stature. [1913 Webster]