From King Dictionary of Contemporary English sincerity sin‧cer‧i‧ty / sɪnˈserəti / noun [uncountable ] HONEST when someone is sincere and really means what they are saying OPP insincerity I don’t doubt her sincerity, but I think she’s got her facts wrong. May I say in all sincerity that we could not have achieved this much without your help and support. Examples from the Corpus sincerity • Consistency and sincerity are very important in the various observances of the rites, ceremonies, duties, and laws. • But sincerity was often indistinguishable from self-absorption. • His deep sincerity helped me to face the future there. • Nothing about his behavior leads me to doubt his sincerity. • It is questionable how much sincerity was behind this maze of proposals and counterproposals in any of the capitals. • The worst effect of organised religion, he said, was its subversion of sincerity and self-knowledge. • How can the nation judge Labour's sincerity if Labour is determined to resist? • Their designer frustrations go well with their expensive sunglasses, but somehow sincerity suffers beneath the hard gloss. • Several people expressed doubts about the sincerity of her offer. • His own pictures are owned by a large number of people, and illustrate the sincerity which was characteristic of him. • "I'll do anything I can to help, " she said with sincerity. in all sincerity • She still puts in occasional appearances, Graves concluded in all sincerity, as a muse to poets like himself! • I cherish his and your friendship, and I can say in all sincerity that Cork would be the poorer without you. • I think in all sincerity it would be better to give up now.