Duck answer when probing business deal? (9)
I believe the answer is:
Here is my best explanation:
'duck' is the definition.
(merganser is a kind of duck)
'answer when probing business deal?' is the wordplay.
'answer' becomes 'ans' (A common abbreviation).
'when probing' indicates putting letters inside (to probe can mean to poke or prod into something).
'business deal?' becomes 'merger' (type of deal in which multiple businesses merge).
'ans' inserted into 'merger' is 'MERGANSER'.
(Other definitions for merganser that I've seen before include "diving duck", "fish-eating duck", "Diving bird", "Diver", "Together saw bill", "Duck", "DUCK", "Diving duck" and "Sawbill".)