brithyll

== Welsh == === Etymology === From brith +‎ -yll. === Noun === brithyll m (plural brithyllod or brithylliaid) trout, brown trout === Mutation === === References === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “brithyll”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies