grey jay vs gray jay

grey jay and gray jay both are nouns.

Word	Noun	Adjective	Verb	Adverb
grey jay	Yes	No	No	No
gray jay	Yes	No	No	No

As nouns, grey jay and gray jay are synonyms defined as:

grey jay and gray jay: a jay of northern North America with black-capped head and no crest; noted for boldness in thievery

Other synonyms of grey jay include camp robber, Canada jay, Perisoreus canadensis, whisker jack.

grey jay (noun)	gray jay (noun)
a jay of northern North America with black-capped head and no crest; noted for boldness in thievery	a jay of northern North America with black-capped head and no crest; noted for boldness in thievery