1) As luck would have it 2) Blissfully 3) Blithely 4) Brightly 5) Cheerfully 6) Cheerily 7) Ecstatically 8) For joy 9) Gayly 10) Gladly 11) In a joyous manner 12) In an unexpectedly lucky way 13) Joyfully 14) Jubilantly 15) Merrily 16) Mirthfully 17) One way to be married 18) Optimistically 19) Vivaciously 1) Blithely 2) Cheerfully 3) Cheerily 4) Contentedly 5) Fortunately 6) Freely 7) Gayly 8) Joyfully 9) Jubilantly 10) Luckily 11) Merrily 12) Mirthfully 13) Thankfully 14) Willingly 
• (adv.) In a happy manner or state; in happy circumstances; as, he lived happily with his wife. • (adv.) With address or dexterity; gracefully; felicitously; in a manner to success; with success. • (adv.) By chance; peradventure; haply. • (adv.) By good fortune; fortunately; luckily.
Hap'pi·ly (hăp'pĭ*lȳ) adverb [ From Happy .] 1. By chance; peradventure; haply. [ Obsolete] Piers Plowman. 2. By good fortune; fortunately; luckily. « Preferred by conquest, happily o'erthrown.» Waller. 3. In a h...
[adv] - in a joyous manner 2. [adv] - in an unexpectedly lucky way
[Othello] (238) [Archaic] haply, by chance.
mirthfully adverb in a joyous manner; `they shouted happily` adverb in an unexpectedly lucky way; `happily he was not injured`