Some refused a mouldy cheese (4)
I believe the answer is:
edam
'cheese' is the definition.
(Edam is an example)
'some refused a mouldy' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'EDAM' can be found hidden inside 'refused a mouldy'.
(Other definitions for edam that I've seen before include "Dairy product" , "edible sphere" , "Dutch 8 across" , "Mild yellow Dutch cheese" , "Made into popular cheese" .)