Adjectives

(s)grey, gray, grey-haired, gray-haired, grey-headed, gray-headed, grizzly, hoar, hoary, white-hairedshowing characteristics of age, especially having grey or white hair“whose beard with age is hoar” (Coleridge), “nodded his hoary head”
(s)hoary, rustyancient“hoary jokes”
(s)canescent, hoarycovered with fine whitish hairs or down