Large order for drink (5)
I believe the answer is:
lager
'for drink' is the definition.
(lager is a kind of drink)
'large order' is the wordplay.
'order' indicates anagramming the letters.
'large' is an anagram of 'LAGER'.
(Other definitions for lager that I've seen before include "Drink - 5 down (anag)" , "Pilsner, for example" , "The drink could be regal" , "Local offering" , "light ale" .)