Troublemaker or terrorist? Not to fans! (7)
I believe the answer is:
stirrer
'troublemaker' is the definition.
(I've seen this before)
'terrorist? not to fans' is the wordplay.
'not' indicates named letters should be taken away.
'fans' indicates an anagram (I've seen 'fanned' mean this (I've seen this in other clues)).
'terrorist' with 'to' taken away is 'errrist'.
'errrist' is an anagram of 'STIRRER'.
'or' acts as a link.
(Other definitions for stirrer that I've seen before include "Troublemaker (informal)" , "Troublesome" , "Spoon - agitator" , "Implement for mixing" , "Scaremonger" .)