WordNet sense 1 (showing characteristics of age, especially having grey or white hair):

gray, grey, grizzly, gray-haired, gray-headed, grey-haired, grey-headed, hoar, white-haired

WordNet sense 2 ((used especially of persons) having lived for a relatively long time or attained a specific age):

old

WordNet sense 3 (ancient):

rusty

WordNet sense 4 (covered with fine whitish hairs or down):

canescent

WordNet sense 5 (having or covered with hair):

haired, hairy, hirsute