From Middle Welsh ieith, from Proto-Brythonic *jeiθ, from Proto-Celtic *yaxtī (compare Breton yezh (“language”), Cornish yeth (“language”), Irish icht (“tribe, people”)), from Proto-Indo-European *yek- (compare Latin jocus (“joke”), Old High German jehan (“to admit, to confess”), Tocharian A yask (“to demand, to beg”)).
iaith f (plural ieithoedd)
|Note: Some of these forms may be hypothetical. Not every
possible mutated form of every word actually occurs.