i Register
In some senses, merrymake is marked as archaic, literary. Watch for register when choosing this word.
verb
To make merry, have fun, celebrate.
Drawing near, / Loud from the chambers of the bridge below, / Sounds of carousal came and song, / And unveiled women bade the advancing youth / Come merry-make with them.
noun
Merry-making, celebration, festivity.
when he saw her toy, and gibe, and geare, / And passe the bonds of modest merimake, / Her dalliance he despisd, and follies did forsake.