grey-headed vs gray-haired

grey-headed and gray-haired both are adjectives.

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

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

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

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

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