Here are some ways to express a higher degree of "merry":
Comparative:
* Merrier: While not as common, this form is grammatically correct.
* More merry: This is the most common and natural way to express a higher degree of "merry."
Superlative:
* Merriest: Again, this form is grammatically correct, but less common.
* Most merry: This is the most common and natural way to express the highest degree of "merry."
Alternatives:
You can also use synonyms to convey different degrees of happiness or joy:
* More cheerful: This is a more neutral alternative to "merrier."
* Most joyful: This emphasizes a strong feeling of happiness.
Ultimately, the best way to express the comparative and superlative of "merry" depends on the specific context and the desired level of formality.