Male fowl (6)
'male fowl' is the definition.
(male chicken)
This is the entire clue.
(Other definitions for rooster that I've seen before include "Farmyard fowl" , "Chanticleer" , "Male hen" , "Farmyard bird" , "Male domestic fowl (US)" .)
(Other definitions for cock that I've seen before include "Rooster" , "Chanticleer" , "early rouser" , "pile of stuff in field?" , "sunshine" .)
(Other definitions for gander that I've seen before include "glance" , "Looking at something - ranged (anag)" , "Male goose; look (colloq.)" , "town in Newfoundland" , "A butcher's -- bird" .)