Convivial (5)
I believe the answer is:
merry
'convivial' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for merry that I've seen before include "Fjull of fun and gaiety" , "Jolly and gay" , "Old King Cole was a ..... old soul" , "Jolly and bright" , "Cheerful, lively" .)