rhiain y dŵr

== Welsh == === Etymology === Literally, “maiden of the water”. === Noun === rhiain y dŵr f (plural rhianedd y dŵr) pond skater, water strider (Gerridae) === Mutation === === Further reading === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “rhiain y dŵr”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies