Informers with partners impounding ship (5)
I believe the answer is:
narks
'informers' is the definition.
(I know this)
'partners impounding ship' is the wordplay.
'partners' becomes 'ns' (North and South are partners in the game bridge).
'impounding' means one lot of letters goes inside another.
'ship' becomes 'ark' (as in Noah's ark).
'ns' enclosing 'ark' is 'NARKS'.
'with' acts as a link.
(Other definitions for narks that I've seen before include "singers" , "Annoys; informers (sl.)" , "Coppers' ..... are slang police informers" , "Irritates" .)