A frantic bit of a rave? (4)
I believe the answer is:
rant
'a rave?' is the definition.
(I know that rave can be written as rant)
'a frantic bit' is the wordplay.
'bit' indicates a hidden word.
'RANT' can be found hidden inside 'frantic'.
'of' acts as a link.
(Other definitions for rant that I've seen before include "Talk wildly, rave" , "Bombastically declaim" , "Talk wildly and incoherently" , "Talk wildly or violently" , "Harangue, rave" .)