Chicken caught by another bird (6)
I believe the answer is:
craven
'chicken' is the definition.
(both can mean cowardly)
'another bird' is the wordplay.
'another' becomes 'c' (I can't explain this - if you can you should give a lot more credence to this answer).
'bird' becomes 'raven' (raven is a kind of bird).
'c'+'raven'='CRAVEN'
'caught by' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for craven that I've seen before include "Yellow" , "Mean-spirited" , "Cowardly, spineless" , "Chicken-hearted" , "Faint-hearted" .)