Where does “bonhedigeidaf” come from?

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

Ancestry of “bonhedigeidaf”, 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 *-isamosEvery word from Middle Welsh -hafEvery word from Proto-Brythonic -haβ̃