Decorated with diamonds above and below (4)
I believe the answer is:
iced
'above and below' is the definition.
I can't tell whether this defines the answer.
'decorated with diamonds' is the wordplay.
'decorated' becomes 'd' (this could be a standard abbreviation which I don't know about).
'with' means one lot of letters go next to another.
'diamonds' becomes 'ice' (slang term for diamonds).
'd' after 'ice' is 'ICED'.
Can you help me to learn more?
(Other definitions for iced that I've seen before include "Chilled - killed" , "Decorated; killed" , "Decorated with sugary mixture" , "Made very cold" , "Decorated (a cake)" .)