ineffable
adjective /ɪnˈefəbl/
/ɪnˈefəbl/
(formal)- too great or beautiful to describe in words
（美好得）难以形容的，不可言喻的 - ineffable joy
难以形容的喜悦
词源late Middle English: from Old French, or from Latin ineffabilis, from in- ‘not’ + effabilis (from effari ‘utter’). - ineffable joy