We don't have synonyms for crwth yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are crith, crowth and cruth.
(n) :
(historical) An archaic stringed instrument associated particularly with Wales, though once played widely in Europe, and characterized by a vaulted back and enough space for the player to stop each of the six strings on the fingerboard. Played variously by plucking or bowing.
(n) :
(historical) An archaic stringed instrument associated particularly with Wales, though once played widely in Europe, and characterized by a vaulted back and enough space for the player to stop each of the six strings on the fingerboard. Played variously by plucking or bowing.