Make a mockery of empty double bed (6)
I believe the answer is:
debunk
'make a mockery of' is the definition.
(debunk can mean to mock or disrespect)
'empty double bed' is the wordplay.
'empty' says to hollow out the word (remove centre letters).
'bed' becomes 'bunk' (bunk is a kind of bed).
'double' with its middle taken out is 'de'.
'de'+'bunk'='DEBUNK'
(Other definitions for debunk that I've seen before include "Expose (pretentious claims?)" , "Show to be falsely honoured" , "Show to be false or unjustified" , "Expose pretensions of" , "Show to be exaggerated or false, claim or theory" .)