Cheap wine, burgundy almost knocked over — fool! (7)
I believe the answer is:
plonker
'fool' is the definition.
(I know that fool can be written as plonker)
'cheap wine burgundy almost knocked over' is the wordplay.
'cheap wine' becomes 'plonk' (plonk can informally mean cheap wine).
'burgundy' becomes 'red' (burgundy is a shade of red).
'almost' means to remove the last letter (most of the word but not all of it).
'knocked over' says the letters should be written backwards.
'red' with its final letter taken off is 're'.
're' reversed gives 'er'.
'plonk'+'er'='PLONKER'
(Other definitions for plonker that I've seen before include "Fool (slang)" , "Fool - smacking kiss" , "Inept person (slang)" , "Stupid person" , "Foolish person - smacking kiss" .)