Welsh traeth

← Breton traezh (cognate)

← Proto-Brythonic *traɨθ (inherited)

← Proto-Celtic *traxtus (inherited)

← Irish trácht (cognate)

← Cornish treth (cognate)

← Middle Welsh traeth (inherited)

→ Breton traezh (cognate)

→ Welsh traethell (affix)

→ Cornish treth (cognate)

→ Old Irish tracht (cognate)