llysiau'r cwsg

== Welsh == === Etymology === Literally "the sleep's herbs". === Noun === llysiau'r cwsg (plural, singular llysieuyn y cwsg m) alternative form of llysiau cwsg (“opium poppy”) === Further reading === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “llysiau”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies