From Longman Dictionary of Contemporary Englishsinceritysin‧cer‧i‧ty /sɪnˈserəti/ noun [uncountable] HONESTwhen 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. 