Frantic romantic gets rid of the rot (5)
I believe the answer is:
manic
'frantic' is the definition.
(both can mean frenzied)
'romantic gets rid of the rot' is the wordplay.
'gets rid of' indicates named letters should be taken away.
'romantic' with 'rot' removed is 'MANIC'.
(Other definitions for manic that I've seen before include "Wildly energetic" , "Frenzied" , "Berserk" , "on one!" , "Wildly excited" .)