trochydd gyddfddu

== Welsh == === Alternative forms === trochydd gwddfddu === Etymology === trochydd (“diver, loon”) + gyddfddu (“black-necked, black-throated”). === Noun === trochydd gyddfddu f (plural trochyddion gyddfddu) black-throated diver, black-throated loon (Gavia arctica) Synonym: trochydd bach === Mutation === === References ===