Hired feathers on chick disappoint (3,4)
I believe the answer is:
let down
'disappoint' is the definition.
(synonyms)
'hired feathers on chick' is the wordplay.
I cannot quite see how this works, but
'hired' could be 'let' (I've seen this before) and 'let' is found within the answer.
'feathers' could be 'down' (down can mean bird feathers) and 'down' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for let down that I've seen before include "Disappoint or fail - or lengthen garment" , "Disappoint, fail to keep promise" , "deflating" , "Disappoint, betray" , "Failed - deflated" .)