Synonyms for Grey-headed (same or very similar meaning)
WordNet sense 1 (showing characteristics of age, especially having grey or white hair):
gray, grey, grizzly, hoary, gray-haired, gray-headed, grey-haired, hoar, white-hairedWordNet sense 2 ((used especially of persons) having lived for a relatively long time or attained a specific age):
oldFrom the ODE community, based on WordNetadd/edit