Corrupt deputy, half gone at party (7)
I believe the answer is:
'corrupt' is the definition.
(I know that corrupt can be written as deprave)
'deputy half gone at party' is the wordplay.
'half gone' indicates taking half.
'at' means one lot of letters go next to another.
'party' becomes 'rave' (type of dance party).
'deputy' with half the letters taken is 'dep'.
(Other definitions for deprave that I've seen before include "Pervade (anag.)" , "Make corrupt" .)