Duck first of misfortunes, in fix (4)
I believe the answer is:
smew
'duck' is the definition.
(I know that smew is a type of merganser)
'first of misfortunes in fix' is the wordplay.
'first of misfortunes' becomes 'm' (1st letter of 'misfortunes').
'in' indicates putting letters inside.
'fix' becomes 'sew' (sewing is a kind of fixing).
'm' placed into 'sew' is 'SMEW'.
(Other definitions for smew that I've seen before include "Diver" , "Species of merganser" , "Small merganser" , "Sea duck" , "Bird" .)