Irish dea-

← Proto-Celtic *degos (inherited)

← Proto-Celtic *dagos (mention)

← Welsh da (cognate)

← Old Irish deg- (inherited)

← Old Irish dag (mention)

→ Welsh da (cognate)

→ Irish dea-mhéin (affix)

→ Irish dea-chruthach (affix)

→ Irish dea-cháil (affix)

→ Irish dea-bhriathar (affix)

→ Cornish dâ (cognate)