Welsh tenau

← Proto-Celtic *tanauyos (inherited)

← Ancient Greek ταναός (cognate)

← Proto-Indo-European *ténh₂us (inherited)

← Latin tenuis (cognate)

← Old Norse þunnr (cognate)

← Old Irish tanae (cognate)

→ English thin (cognate)

→ Irish tanaí (cognate)

→ Old Irish tanae (cognate)