Warder, female, feeding bird (9)
I believe the answer is:
beefeater
'warder' is the definition.
(Beefeater can informally mean a Yeomen Warder)
'female feeding bird' is the wordplay.
'female' becomes 'f' (abbreviation).
'feeding' means one lot of letters goes inside another (one word is fed by another set of letters).
'bird' becomes 'beeeater' (bee-eater is a type of bird).
'f' going inside 'beeeater' is 'BEEFEATER'.
(Other definitions for beefeater that I've seen before include "Royal servant" , "Tower of London guard" , "no vegetarian?" , "royal bodyguard" , "Bodyguard of the British monarch" .)