Singer in group getting fill wrong (9)
I believe the answer is:
bullfinch
'singer' is the definition.
(bullfinch is a kind of birdanimal)
'group getting fill wrong' is the wordplay.
'group' becomes 'bunch' ().
'getting' means one lot of letters goes inside another.
'wrong' indicates an anagram.
'fill' with letters rearranged gives 'llfi'.
'bunch' going around 'llfi' is 'BULLFINCH'.
'in' acts as a link.
(Other definitions for bullfinch that I've seen before include "Bird that eats fruit buds" , "Common garden bird" , "Bird with pink-breasted male" , "hedge" .)