Worker at first refuses drink (4)
I believe the answer is:
beer
'drink' is the definition.
(I know that beer is a type of beer)
'worker at first refuses' is the wordplay.
'worker' becomes 'bee' (a worker bee).
'at' is a charade indicator (letters next to each other).
'first refuses' becomes 'r' (bst letter of 'refuses').
'bee'+'r'='BEER'
(Other definitions for beer that I've seen before include "Malt liquor" , "... this at pub?" , "Drink using hops, malt, etc" , "pint" , "Drink flavoured with hops" .)