Hir a thoddaid is a traditional Welsh syllabic verse form made of a long line followed by a toddaid line. It belongs to the strict Welsh poetic tradition, where sound patterning and careful line structure matter as much as syllable count. Poets use it for formal, musical poems shaped by Welsh prosody.
Example
The river keeps its silver in the dusk,
while reeds lean down and comb the mirrored dark.