Festively means pertaining to or suitable for a feast or a festival.

Example: Festive party hall; We walked down the street festively

This refers to a popular line of holiday decor items found at the store "Pottery Barn". Practical household items (mugs, etc.) that feature festively painted reindeer.

Merrily means in a cheerful and lively manner, with happiness or joy. It is often used to describe someone who is in good spirits or is having a good time.

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 4 words with the pattern F-S-IV---. That is, nine letter words with 1st letter F and 3rd letter S and 5th letter I and 6th letter V. In alphabetical order, they are:

festivals

festively

festivity

festivous

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 7 words with the pattern -E-T-V---. That is, nine letter words with 2nd letter E and 4th letter T and 6th letter V. In alphabetical order, they are:

aestivate

festivals

festively

festivity

festivous

leftovers

restively