Proto-Celtic *reteti

→ Welsh dod (mention)

→ Welsh rhedeg (inherited)

→ Irish rith (inherited)

→ Irish tóir (mention)

→ Scottish Gaelic ruith (inherited)

→ Manx roie (inherited)

→ Cornish resek (inherited)

→ Old Irish reithid (inherited)

→ Old Irish comthururas (derived)

→ Middle Welsh redec (inherited)