The Collaborative International Dictionary of English v.0.48:
Hoariness \Hoar"i*ness\, n. [From Hoary.] The state of being hoary. --Dryden. [1913 Webster]WordNet (r) 3.0 (2006):
hoariness n 1: a silvery-white color [syn: frostiness, hoariness] 2: great age (especially grey or white with age)