A short poem; properly, a short pastoral poem; as, the idyls of Theocritus; also, any poem, especially a narrative or descriptive poem, written in an eleveted and highly finished style; also, by extension, any artless and easily flowing description, either in poetry or prose, of simple, rustic life, of pastoral scenes, and the like.
Either a short poem depicting a peaceful, idealized country scene, or a long poem that tells a story about heroic deeds or extraordinary events set in the distant past. Idylls of the King, by Alfred Lord Tennyson, is about King Arthur and the Knights of the Round Table.