llygredd

== Welsh == === Etymology === From llwgr +‎ -edd. === Noun === llygredd m (plural llygreddau) corruption pollution, contamination === Mutation === === Further reading === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “llygredd”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies