Gregorian mode vs medieval mode

Gregorian mode and medieval mode both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gregorian mode	Yes	No	No	No
medieval mode	Yes	No	No	No

As nouns, Gregorian mode and medieval mode are synonyms defined as:

Gregorian mode and medieval mode: any of a system of modes used in Gregorian chants up until 1600; derived historically from the Greek mode

Other synonyms of Gregorian mode include church mode, ecclesiastical mode.

Gregorian mode (noun)	medieval mode (noun)
any of a system of modes used in Gregorian chants up until 1600; derived historically from the Greek mode	any of a system of modes used in Gregorian chants up until 1600; derived historically from the Greek mode