Shocking twisted Nazi mag (7)
I believe the answer is:
amazing
'shocking' is the definition.
(thesaurus)
'twisted nazi mag' is the wordplay.
'twisted' indicates anagramming the letters.
'nazi'+'mag'='nazimag'
'nazimag' with letters rearranged gives 'AMAZING'.
(Other definitions for amazing that I've seen before include "Filling with wonder, a huge surprise" , "Causing wonder" , "Astonishing, wonderful" , "Astounding, awe-inspiring" , "Gobsmackingly great!" .)