Welsh buwch

← Breton buoc’h (cognate)

← Proto-Brythonic *bʉx (inherited)

← Proto-Celtic *boukkā (inherited)

← Proto-Celtic *bāus (mention)

← Proto-Indo-European *gʷṓws (derived)

← Cornish bugh (cognate)

← Old Irish bó (cognate)

← Middle Welsh buch (inherited)

← Middle Welsh bu (cognate)

→ Breton buoc'h (cognate)

→ Welsh maer biswail (mention)

→ Welsh buchod (affix)

→ Welsh buwch goch gota (affix)

→ Cornish bugh (cognate)

→ Cornish buwgh (cognate)