Source : Webster's Revised Unabridged Dictionary (1913)

Hoary \Hoar"y\, a.
   1. White or whitish. ``The hoary willows.'' --Addison.

   2. White or gray with age; hoar; as, hoary hairs.

            Reverence the hoary head.             --Dr. T.
                                                  Dwight.

   3. Hence, remote in time past; as, hoary antiquity.

   4. Moldy; mossy; musty. [Obs.] --Knolles.

   5. (Zo["o]l.) Of a pale silvery gray.

   6. (Bot.) Covered with short, dense, grayish white hairs;
      canescent.

   {Hoary bat} (Zo["o]l.), an American bat ({Atalapha cinerea}),
      having the hair yellowish, or brown, tipped with white.

Source : WordNet®

hoary
     adj 1: showing characteristics of age, especially having gray or
            white hair; "whose beard with age is hoar"-Coleridge;
            "nodded his hoary head" [syn: {gray}, {grey}, {gray-haired},
             {grey-haired}, {gray-headed}, {grey-headed}, {grizzly},
             {hoar}, {white-haired}]
     2: ancient; "hoary jokes" [syn: {rusty}]
     3: covered with fine whitish hairs or down [syn: {canescent}]
     [also: {hoariest}, {hoarier}]