Compile extraordinary argument (7)
I believe the answer is:
polemic
'argument' is the definition.
(I know that polemic is a type of argument)
'compile extraordinary' is the wordplay.
'extraordinary' indicates an anagram.
'compile' is an anagram of 'POLEMIC'.
(Other definitions for polemic that I've seen before include "Controversial line of argument" , "Contentious" , "Compile to make verbal attack on belief" , "Fierce spoken or written attack" , "Controversy; attacking speech" .)