Call carvery at last: turkey? It’s not what you would call swan! (5-4)
I believe the answer is:
belly-flop
'not what you would call swan' is the definition.
I can't judge whether this defines the answer.
'call carvery at last turkey?' is the wordplay.
'call' becomes 'bell' (bell can mean a phone call).
'at last' indicates one should take the final letters.
'turkey?' becomes 'flop' (turkey is a kind of flop).
The last letter of 'carvery' is 'y'.
'bell'+'y'+'flop'='BELLY-FLOP'
'it's' is the link.
Can you help me to learn more?
(Other definitions for belly-flop that I've seen before include "Awkward dive" , "Inexpert dive" .)