Love to set up drink after work (4)
I believe the answer is:
opus
'work' is the definition.
(an opus is an artistic work)
'love to set up drink after' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'to set up' says the letters should be written backwards (in a down clue, letters go up).
'drink' becomes 'sup' (to sup is to drink).
'after' means one lot of letters go next to another.
'sup' backwards is 'pus'.
'o'+'pus'='OPUS'
(Other definitions for opus that I've seen before include "Showing creative skill" , "(Numbered) musical composition" , "Major work" , "Work (mus.)" , "Work of 25 perhaps" .)