The Muse of comedy (6)
I believe the answer is:
thalia
'the muse of comedy' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for thalia that I've seen before include "Greek Muse of comedy" , "Inspiring female" , "source of artistic inspiration" , "Aha, lit up one of the three Graces of Greek mythology" , "Grace" .)