Hurt mutant with radical rage (7)
I believe the answer is:
tantrum
'rage' is the definition.
(thesaurus)
'hurt mutant with radical' is the wordplay.
'hurt' indicates an anagram.
'with' means one lot of letters goes inside another.
'radical' becomes 'r' (chemistry abbreviation).
'mutant' with letters rearranged gives 'tantum'.
'tantum' placed around 'r' is 'TANTRUM'.
(Other definitions for tantrum that I've seen before include "Uncontrolled outburst of anger" , "throwing this?" , "Wobbly" , "Hissy fit" , "Pet, temper" .)