Drink, awfully big and green, set before Queen (6,4)
I believe the answer is:
ginger beer
'drink' is the definition.
(ginger beer is a kind of drink)
'awfully big and green set before queen' is the wordplay.
'awfully' indicates anagramming the letters.
'and' means one lot of letters go next to another.
'set before' says to put letters next to each other.
'queen' becomes 'ER' (short for Elizabeth Regina ie Queen Elizabeth).
'big' after 'green' is 'greenbig'.
'greenbig' with letters rearranged gives 'gingerbe'.
'gingerbe'+'er'='GINGER-BEER'
(Other definitions for ginger beer that I've seen before include "Sparkling drink" , "Spicy drink" , "Non-alcoholic drink" , "Fizzy drink" .)