cramen y cerrig

== Welsh == === Etymology === Literally “skin of the rocks”. === Noun === cramen y cerrig f (uncountable) lichen (on rocks) ==== Synonyms ==== cen === Mutation === === References === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “cramen y cerrig”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies