A bird and a male one, furthermore (8)
I believe the answer is:
cockatoo
'a bird' is the definition.
(cockatoo is a kind of bird)
'a male one furthermore' is the wordplay.
'a male' becomes 'cock' (male chicken).
'one' becomes 'a' (a thing is one thing).
'furthermore' becomes 'too' (I've seen this before).
'cock'+'a'+'too'='COCKATOO'
'and' acts as a link.
(Other definitions for cockatoo that I've seen before include "Crested bird" , "Bird, a type of parrot" , "Australasian parrot" , "White parrot" , "Australian parrot" .)