How many letters does the top answer for “mirth; frolic; a meeting for mirth; a festival.” have?

The most common answer is merrymake (9 letters).

Crossword clue: mirth; frolic; a meeting for mirth; a festival.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

merrymake 9 letters web-def

Mirth; frolic; a meeting for mirth; a festival. [Written also merrimake.]

a meeting for mirth. 50% similar → merrymeeting