(prosody) The complex system of internal assonance, alliteration and rhyme in Welsh strict-meter poetry.
Only certain epithets and metaphors were authorized; themes were similarly restricted, metres fixed, and Cynghanedd, the repetitive use of consonantal sequences with variation of vowels, became a burdensome obsession.
1998, editors (names unknown), "cynghanedd" in Britannica Online Encyclopedia
There are four fundamental types of cynghanedd, but within these there are a number of refinements and variations. When skillfully used, cynghanedd is capable of conveying an almost unlimited variety of subtle effects.