Difference between Merrily and Happily

MERRILY vs HAPPILY: ADVERB

In a joyous manner
In a cheerful or merry manner.
In a merry manner; with mirth; with gayety and laughter; jovially. See mirth, and merry.

In a happy manner or state; in happy circumstances.
With address or dexterity; gracefully; felicitously; in a manner to insure success; with success.
By chance; perhaps.
By good chance; fortunately, successfully.
In a happy or cheerful manner; with happiness.
In a joyous manner
In an unexpectedly lucky way
With good will; in all happiness; willingly.

By good fortune; fortunately; luckily.
In a happy or pleasing way or state; in pleasant or fortunate circumstances; with happiness or joy.
With address, skill, dexterity, or aptness; dexterously; felicitously; aptly; gracefully.
Synonyms Haply, Happily. Haply, now rarely used in prose, means by chance; happily, by a happy chance.
Prosperously, successfully, contentedly.
By chance; peradventure; haply.

Joyously, Joyfully, Cheerfully, Gleefully, Gay, Fortunately, Luckily, Mercifully, Gaily, With happiness, Gayly, Mirthfully, Jubilantly, Happily, Blithely

Comfortably, Pleasantly, Quietly, Gaily, Willingly, Enthusiastically, Gladly, Cheerfully, Joyfully, With happiness, Gayly, Mirthfully, Jubilantly, Blithely, Merrily

Dutifully, Blissfully, Noisily, Nonchalantly, Lazily, Contentedly, Joyously, Gay, Fortunately, Luckily, Mercifully, Gaily, Gayly, Mirthfully, Blithely

Delightfully, Seamlessly, Happier, Happy, Readily, Comfortably, Pleasantly, Quietly, Gaily, Willingly, Gladly, Gayly, Mirthfully, Blithely, Merrily

Section 1 title sits merrily on the horizon.
The Princess hugged me close and laughed merrily.
Credit Acceptance, but the industry rolled merrily along.
Hot Cross Buns or Merrily We Roll Along.
And never more merrily than in these pages.
Merrily Dicks also received her Paul Harris Fellow.
The sea was calm and the sky was blue; Merrily, merrily sailed we two.
They quickly had the crowd merrily clapping in time and merrily joining in on the chorus.
Merrily, merrily shall I live now Under the blossom that hangs on the bough.
Merrily, merrily, merrily, merrily, life is but a dream!

We are both happily starting the maintenance program.
You can definitely barhop happily on that street.
Brazil heist finally living happily and in peace.
Gobble them down happily along with your coworkers.
Shayna grew up dreaming about happily every after.
Politely say no and live your life happily.
We will happily recommend you at any opportunity.
Williams and Dunst, happily, are the real stars.
He happily gave up everything for us and when we realized this we happily give up everything for him.
There are enough retailers out there that will happily accommodate their customers and I will happily patronize them!