Conservative about depravity in Split (7)
I believe the answer is:
crevice
'split' is the definition.
(I know that split can be written as crevice)
'conservative about depravity' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'about' becomes 're' ('re' means regarding or about).
'depravity' becomes 'vice' (moral depravity).
'c'+'re'+'vice'='CREVICE'
'in' is the link.
(Other definitions for crevice that I've seen before include "Cleft, fissure" , "Narrow crack" , "Narrow rock fissure" , "Opening" , "Crack or fissure." .)