Knock back Burgundy perhaps with one cold drink (5)
I believe the answer is:
cider
'drink' is the definition.
(I know that cider is a type of drink)
'knock back burgundy perhaps with one cold' is the wordplay.
'knock back' says the letters should be written in reverse.
'burgundy perhaps' becomes 'red' (burgundy is a kind of red).
'with' says to put letters next to each other.
'one' becomes 'i' (Roman numeral).
'cold' becomes 'C' (eg on taps).
'red'+'i'+'c'='redic'
'redic' back-to-front is 'CIDER'.
(Other definitions for cider that I've seen before include "Apple-based beverage" , "Alcoholic drink (to be taken with Rosie?)" , "Drink made from pears" , "Drink made from fermented apples" , "Beverage from apple juice" .)