Sore about the defiant expression (2,5)
I believe the answer is:
so there
'defiant expression' is the definition.
(I've seen this before)
'sore about the' is the wordplay.
'about' is an insertion indicator.
'sore' going around 'the' is 'SO THERE'.
(Other definitions for so there that I've seen before include "Expression of triumph, derision, etc" , "defiant expression" , "What are you going to do about that" , "Expression of defiance" , "Tough!" .)