Bishop said to be covered in fat! (8)
I believe the answer is:
buttered
'covered in fat' is the definition.
'buttered' can be an answer for 'covered' (buttering is a kind of covering). I am unsure of the 'in fat' bit.
'bishop said' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'said' becomes 'uttered' (I've seen this in another clue).
'b'+'uttered'='BUTTERED'
'to be' acts as a link.
Can you help me to learn more?
(Another definition for buttered that I've seen is " Covered with dairy spread".)