Satisfy need initially in criminal depravity (8)
I believe the answer is:
'satisfy' is the definition.
(I've seen this before)
'need initially in criminal depravity' is the wordplay.
'initially' says to take the initial letters.
'in' is an insertion indicator.
'criminal' becomes 'con' (abbreviation for 'convict').
'depravity' becomes 'vice' (I've seen this before).
The first letter of 'need' is 'n'.
'n' placed into 'convice' is 'CONVINCE'.
(Other definitions for convince that I've seen before include "Persuade someone of the truth of something" , "Persuade successfully" , "Be persuasive" , "Win over to your point of view" , "Make believe" .)