Aggressive type fends off differences (6)
I believe the answer is:
fierce
'aggressive' is the definition.
(thesaurus)
'type fends off differences' is the wordplay.
'type' indicates anagramming the letters.
'off' indicates named letters should be taken away.
'differences' with 'fends' taken out is 'ifrece'.
'ifrece' anagrammed gives 'FIERCE'.
(Other definitions for fierce that I've seen before include "Ferocious, intense" , "Violent in temper, not gentle" , "Ferocious, savage" , "Powerfully aggressive" , "intensity" .)