grey-haired vs gray-headed

grey-haired and gray-headed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
grey-haired	No	Yes	No	No
gray-headed	No	Yes	No	No

As adjectives, grey-haired and gray-headed are synonyms defined as:

grey-haired and gray-headed: showing characteristics of age, especially having grey or white hair

Other synonyms of grey-haired include gray-haired, gray, grey-headed, grey, grizzly, hoar, hoary, white-haired.

grey-haired (adjective)	gray-headed (adjective)
showing characteristics of age, especially having grey or white hair	showing characteristics of age, especially having grey or white hair