信誓旦旦 xìnshìdàndàn to vow solemnly Definitions Defs Origin Strokes Stroke Words Sentences Sents 信誓 xìnshì faithful oath faithful oaths or pledges; a solemn promise made in good faith旦旦 dàndàn sincere (literary) sincere and honest; typically used in the phrase 信誓旦旦 xìnshìdàndàn