15 sincerely synonyms include genuinely, honestly, really, with all sincerity, truly, truthfully, wholeheartedly, with all one's heart, and earnestly. Sincerely is an adverb, and its antonyms are insincerely and deceitfully. Here are some additional synonyms for "sincerely" with example sentences.
15 other ways to say sincerely.
He apologized sincerely for his mistake yesterday.
I sincerely appreciate your kind help.
She won't leave unless he apologizes sincerely.