Drink large mead one served up (8)
I believe the answer is:
lemonade
'drink' is the definition.
(I know that Lemonade is a type of ade)
'large mead one served up' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'served up' is an anagram indicator.
'mead'+'one'='meadone'
'meadone' with letters rearranged gives 'emonade'.
'l'+'emonade'='LEMONADE'
(Other definitions for lemonade that I've seen before include "(Usually) fizzy drink" , "This should refresh" , "Soft drink; Noel made (anag.)" , "Mo leaned on the drink" , "Sweet carbonated drink" .)