Busy worker has right drink (4)
I believe the answer is:
beer
'drink' is the definition.
(I know that beer is a type of drink)
'busy worker has right' is the wordplay.
'busy worker' becomes 'bee' (I've seen this in another clue).
'has' says to put letters next to each other.
'right' becomes 'r' (common abbreviation).
'bee'+'r'='BEER'
(Other definitions for beer that I've seen before include "Hop-flavoured drink" , "Brewery product" , "eg Bitter" , "Hopped drink" , "Drink brewed with malt" .)