What is "cynghanedd"

n. (context prosody English) The complex system of internal assonance, alliteration and rhyme in Welsh strict-metre poetry.

In Welsh language poetry, cynghanedd (, literally " harmony") is the basic concept of sound-arrangement within one line, using stress, alliteration and rhyme. The various forms of cynghanedd show up in the definitions of all formal Welsh verse forms, such as the awdl and cerdd dafod. Though of ancient origin, cynghanedd and variations of it are still used today by many Welsh-language poets. A number of poets have experimented with using cynghanedd in English-language verse, for instance Gerard Manley Hopkins. Some of Dylan Thomas's work is also influenced by cynghanedd.