... drink always imbibed by British date (8)
I believe the answer is:
beverage
'drink' is the definition.
(I know that drink can be written as beverage)
'always imbibed by british date' is the wordplay.
'always' becomes 'ever' (synonyms).
'imbibed by' indicates putting letters inside.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'date' becomes 'age' (both can mean to get older).
'b'+'age'='bage'
'ever' placed inside 'bage' is 'BEVERAGE'.
(Other definitions for beverage that I've seen before include "Tea, say" , "Drink other than water" , "Any drink, say a beer" , "Liquid for drinking" , "Non-alcoholic drink" .)