Bishop always on time for a drink (8)
I believe the answer is:
beverage
'for a drink' is the definition.
(synonyms)
'bishop always on time' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'always' becomes 'ever' (synonyms).
'on' means one lot of letters go next to another.
'time' becomes 'age' (an age is a period of time).
'b'+'ever'+'age'='BEVERAGE'
(Other definitions for beverage that I've seen before include "Any drink, say a beer" , "Prepared drink" , "Non-alcoholic drink" , "Tea, say" , "Liquid refreshment" .)