Old Irish réud

← Proto-Celtic *ɸreswos (inherited)

← English freeze (cognate)

← Proto-Indo-European *prews- (inherited)

← Latin pruina (cognate)

→ Welsh rhew (cognate)

→ Irish reo (inherited)

→ Scottish Gaelic reòth (mention)

→ Manx rio (inherited)

→ Middle Irish reód (inherited)