composition vs idyl

composition and idyl both are nouns.

Word	Noun	Adjective	Verb	Adverb
composition	Yes	No	No	No
idyl	Yes	No	No	No

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

composition (noun)	idyl (noun)
the act of creating written works	a short poem descriptive of rural or pastoral life
musical creation	a musical composition that evokes rural life
something that is created by arranging several things to form a unified whole
the way in which someone or something is composed
the spatial property resulting from the arrangement of parts in relation to each other and to the whole
an essay (especially one written as an assignment)
a musical work that has been created
art and technique of printing with movable type
a mixture of ingredients