Short reply in combination with diver (9)
I believe the answer is:
merganser
'diver' is the definition.
(I've seen this before)
'short reply in combination' is the wordplay.
'short reply' becomes 'ans' (abbreviation for answer; 'short' indicates a short form).
'in' is an insertion indicator.
'combination' becomes 'merger' (merger is a kind of combination).
'ans' placed inside 'merger' is 'MERGANSER'.
'with' acts as a link.
(Other definitions for merganser that I've seen before include "Diving duck" , "Diving bird" , "Sawbill" , "Together saw bill" , "Diver" .)