Greek key vs key pattern

Greek key and key pattern both are nouns.

Word	Noun	Adjective	Verb	Adverb
Greek key	Yes	No	No	No
key pattern	Yes	No	No	No

As nouns, Greek key and key pattern are synonyms defined as:

Greek key and key pattern: an ornamental pattern consisting of repeated vertical and horizontal lines (often in relief)

Other synonyms of Greek key include fret, Greek fret.

Greek key (noun)	key pattern (noun)
an ornamental pattern consisting of repeated vertical and horizontal lines (often in relief)	an ornamental pattern consisting of repeated vertical and horizontal lines (often in relief)