Madden crazed Hun in, say, uprising (7)
I believe the answer is:
unhinge
'madden' is the definition.
(I've seen this before)
'crazed hun in say uprising' is the wordplay.
'crazed' indicates anagramming the letters (I've seen this in other clues).
'say' becomes 'eg'.
'uprising' says the letters should be written in reverse.
'eg' written backwards gives 'ge'.
'hun' with letters rearranged gives 'unh'.
'unh'+'in'+'ge'='UNHINGE'
(Other definitions for unhinge that I've seen before include "Remove a door - or drive insane" , "Remove a gate from its support" , "Drive mad or destabilize door" , "Drive mad in huge inn" , "Drive demented in huge inn" .)