Gregorian mode vs church mode

Gregorian mode and church mode both are nouns.

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

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

Gregorian mode and church 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 ecclesiastical mode, medieval mode.

Gregorian mode (noun)	church 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