Welsh onn

← Breton onn (mention)

← Proto-Brythonic *onnā (inherited)

← Proto-Celtic *osno (inherited)

← English ash (cognate)

← Proto-Indo-European *h₃es-n- (inherited)

← Latin ornus (cognate)

← Old Irish uinnius (cognate)

→ English Ann (cognate)

→ Old Irish uinnius (cognate)