Neidio i'r prif gynnwy

Saesneg: oxbow lake

Cymraeg: ystumllyn

Rhan ymadrodd

Enw, Gwrywaidd, Unigol

Diffiniad

Curved lake found on the flood plain of a river. Oxbows are caused by the loops of meanders that are cut off at times of flood and the river subsequently adopts a shorter course.