Cornish treth

← Breton traezh (cognate)

← Proto-Brythonic *traɨθ (inherited)

← Proto-Celtic *traxtus (inherited)

← Middle Cornish treath (inherited)

← Welsh traeth (cognate)

← Irish trácht (cognate)

← Old Cornish trait (inherited)

→ Breton traezh (cognate)

→ Welsh traeth (cognate)

→ Cornish trethow (suffix)