Antonyms of adv sincerely

1 of 2 senses of sincerely

Sense 1
sincerely, unfeignedly, truly -- (with sincerity; without pretense; "she praised him sincerely for his victory"; "was unfeignedly glad to see his old teacher"; "we are truly sorry for the inconvenience")
       Antonym of insincerely (Sense 1)
      => insincerely -- (without sincerity; "she congratulated him somewhat insincerely")

Synonyms of adv sincerely

2 senses of sincerely

Sense 1
sincerely, unfeignedly, truly -- (with sincerity; without pretense; "she praised him sincerely for his victory"; "was unfeignedly glad to see his old teacher"; "we are truly sorry for the inconvenience")

Sense 2
sincerely, sincerely yours -- (written formula for ending a letter)