sin ‧ cere ‧ ly /sɪnˈsɪəli $ -ˈsɪr-/ BrE AmE adverb
1 . if you feel or believe something sincerely, you really feel or believe it and are not just pretending SYN truly :
I sincerely hope I’ll see her again.
We are sincerely grateful for your help.
2 . (yours) sincerely an expression used to end a formal letter, especially one that you have begun by using someone’s name