Where does “kyweiraf” come from?

kyweiraf (Middle Welsh) comes from Middle Welsh -haf, from Proto-Brythonic -haβ̃, from Proto-Celtic *-isamos — forms superlative adjectives.

Ancestry of “kyweiraf”, step by step

StepLanguageWordMeaning
1Middle Welsh-hafused to form the superlative of an adjective
2Proto-Brythonic-haβ̃Forms the superlative of an adjective
3Proto-Celtic*-isamosforms superlative adjectives
Every word from Proto-Celtic *-isamos →Every word from Middle Welsh -haf →Every word from Proto-Brythonic -haβ̃ →