We go in building and duck (6)
I believe the answer is:
wigeon
'duck' is the definition.
(wigeon is a kind of duck)
'we go in building' is the wordplay.
'building' indicates anagramming the letters.
'we'+'go'+'in'='wegoin'
'wegoin' is an anagram of 'WIGEON'.
'and' acts as a link.
(Other definitions for wigeon that I've seen before include "Freshwater duck" , "Duck, related to mallard and teal" , "Type of duck" , "Duck with whistling call" , "Breed of duck" .)