Source : Webster's Revised Unabridged Dictionary (1913)

Hoariness \Hoar"i*ness\, n. [From {Hoary}.]
   The state of being hoary. --Dryden.

Source : WordNet®

hoariness
     n 1: a silvery-white color [syn: {frostiness}]
     2: great age (especially gray or white with age)