chwilen ddu fawr

== Welsh == === Etymology === Literally, “large black beetle”. === Noun === chwilen ddu fawr f (plural chwilod duon mawr, not mutable) cockroach (Blattodea) Synonyms: cocrotsien, chwilen ddu === Further reading === Griffiths, Bruce; Glyn Jones, Dafydd (1995), “cockroach”, in Geiriadur yr Academi: The Welsh Academy English–Welsh Dictionary‎[1], Cardiff: University of Wales Press, →ISBN