Husband in army quarters is the winner (5)
I believe the answer is:
champ
'the winner' is the definition.
(I've seen this before)
'husband in army quarters' is the wordplay.
'husband' becomes 'h' (abbreviation).
'in' means one lot of letters goes inside another.
'army quarters' becomes 'camp' (military camp).
'h' placed within 'camp' is 'CHAMP'.
'is' acts as a link.
(Other definitions for champ that I've seen before include "Chew noisily" , "The first person" , "Mashed potato with scallions" , "Crush" , "Top sportsman" .)