A long time for some wage slaves (4)
I believe the answer is:
ages
'a long time' is the definition.
(ages can mean a very long time)
'some wage slaves' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'AGES' is hidden in the letters of 'wage slaves'.
'for' is the link.
(Other definitions for ages that I've seen before include "Historic periods or prolonged time" , "Indefinitely long time" , "A long time (colloq.)" , "Long periods" , "Historical eras" .)