pastoral vs idyll

pastoral and idyll both are nouns.

Word	Noun	Adjective	Verb	Adverb
pastoral	Yes	Yes	No	No
idyll	Yes	No	No	No

As nouns, pastoral and idyll are synonyms defined as:

Other synonyms of pastoral include idyl, pastorale.

As nouns, idyll is a hyponym of pastoral; that is, idyll is a word with a more specific, narrower meaning than pastoral:

pastoral: a literary work idealizing the rural life (especially the life of shepherds)
idyll: a short poem descriptive of rural or pastoral life

Other hyponyms of pastoral include bucolic, eclogue, idyl.

pastoral (noun)	idyll (noun)
a musical composition that evokes rural life	a short poem descriptive of rural or pastoral life
a literary work idealizing the rural life (especially the life of shepherds)	a musical composition that evokes rural life
a letter from a pastor to the congregation	an episode of such pastoral or romantic charm as to qualify as the subject of a poetic idyll

pastoral (adjective)	idyll (adjective)
of or relating to a pastor
relating to shepherds or herdsmen or devoted to raising sheep or cattle
(used with regard to idealized country life) idyllically rustic