Bishop is certain to lose the head on finding gold in writing desk (6)
I believe the answer is:
bureau
'writing desk' is the definition.
(I've seen this before)
'bishop is certain to lose the head on finding gold' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'is certain' becomes 'sure' (synonyms).
'to lose the head' means to remove the first letter (I've seen 'losing the head' mean this).
'on finding gold' becomes 'au' (I can't justify this - if you can you should believe this answer much more).
'sure' with its first letter removed is 'ure'.
'b'+'ure'+'au'='BUREAU'
'in' is the link.
Can you help me to learn more?
(Other definitions for bureau that I've seen before include "Agency - writing desk" , "Writing desk with drawers" , "Room" , "Chest of drawers or office" , "Office; writing desk" .)