Chicken that's sat on, we hear -- one's come down looking embarrassed (5,6,3)
I believe the answer is:
rhode island red
'chicken' is the definition.
(Rhode Island red is an example)
'sat on we hear one's come down looking embarrassed' is the wordplay.
'sat on' becomes 'rode'.
'we hear' shows a homophone (sound like).
'one's' becomes 'is' (Roman numeral).
'come down' becomes 'land' (I've seen this before).
'looking embarrassed' becomes 'red' (someone may go red when embarrassed).
'rode' is a homophone of 'rhode'.
'rhode'+'is'+'land'+'red'='RHODE ISLAND RED'
'that's' acts as a link.
(Other definitions for rhode island red that I've seen before include "New England communist" , "Fowl" , "possible victim of battery" , "Chicken breed" , "American Communist" .)