WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
showing characteristics of age, especially having grey or white hair
noun.
ice crystals forming a white deposit (especially on objects outside)
Word Usage
"Thanks for the kind words, the term hoar frost has an ancient ring to it to my ears and the landscape is beautiful, but I NEED to go outside and piddle around for my mental and physical health."