Pluck wings of excellent young chicken (6)
I believe the answer is:
pullet
'young chicken' is the definition.
(I've seen this before)
'pluck wings of excellent' is the wordplay.
'pluck' becomes 'pull' (synonyms).
'wings of' suggests removing the centre (letters on the two wings removed).
'excellent' with its centre taken out is 'et'.
'pull'+'et'='PULLET'
(Other definitions for pullet that I've seen before include "No high-flyer" , "A young domestic hen less than one year old" , "Young chicken" , "Chicken under one year old" , "Domestic hen less than 1 year old" .)