vespers vs evensong

vespers and evensong both are nouns.

Word	Noun	Adjective	Verb	Adverb
vespers	Yes	No	No	No
evensong	Yes	No	No	No

As nouns, vespers and evensong are synonyms defined as:

vespers and evensong: the sixth of the seven canonical hours of the divine office; early evening; now often made a public service on Sundays

vespers (noun)	evensong (noun)
the sixth of the seven canonical hours of the divine office; early evening; now often made a public service on Sundays	(Anglican Church) a daily evening service with prayers prescribed in the Book of Common Prayer
	the sixth of the seven canonical hours of the divine office; early evening; now often made a public service on Sundays