vow
/vau; vaʊ/ n
solemn promise or undertaking, esp of a religious nature 誓, 誓约, 誓言（尤指宗教的）
recite/pronounce/renew one's `marriage vows 念[发出/重复]自己的婚誓
keep/break a solemn vow 履行[违反]庄严的誓约
take a vow of silence, secrecy, etc 立誓保持沉默、 保守秘密等
Nuns are under vows of poverty, chastity and obedience. 修女须立誓保持清贫、 贞洁、 顺从. vow, v [Tn, Tf, Tt]
make a vow about (sth); swear, promise or declare solemnly 就（某事物）起誓; 立誓; 发誓
They vowed revenge on their enemies. 他们发誓要向敌人报仇.
He vowed (that) he would lose weight. 他立誓要减轻体重.
She vowed never to speak to him again. 她发誓再也不跟他说话了.