ecclesiastical mode vs church mode

ecclesiastical mode and church mode both are nouns.

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

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

ecclesiastical 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 ecclesiastical mode include Gregorian mode, medieval mode.

ecclesiastical 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