Fit of rage (7)
I believe the answer is:
tantrum
'fit of rage' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for tantrum that I've seen before include "petulant outburst" , "Frenzy" , "Fit of ill-temper" , "Burst of rage" , "Childish outbreak of temper" .)