1. (adverb)sincerely, unfeignedly, truly with sincerity; without pretense Synonyms: really, truly, genuinely, rightfully, sincerely yours, in truth, unfeignedly, sincerely Antonyms: insincerely
2. (adverb)sincerely, sincerely yours written formula for ending a letter Synonyms: truly, sincerely, unfeignedly, sincerely yours Antonyms: insincerely