adjective
merrier; -est
somewhat old-fashioned
very happy and cheerful :feeling or showing joy and happiness
causing joy and happiness
go on your merry way
or be on your merry way :to leave a place
often disapproving :to continue doing what you have been doing
lead (someone) a merry chase/dance
make merry
old-fashioned :to have fun and enjoy yourself by eating, drinking, dancing, etc.
Merry Christmas
used to wish someone an enjoyable Christmas holiday
the more the merrier
used to say that more people are welcome or invited to do something
US