Siôn Cwsg

== Welsh == === Etymology === Literally, “John Sleep” === Proper noun === Siôn Cwsg m (not mutable) the sandman Synonym: Huwcyn sleepiness Synonym: cysgadrwydd ==== Related terms ==== Siôn Barrug (“Jack Frost”) === Further reading === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “Siôn Cwsg”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies