Signs nothing and workers succeeded ... (5)
I believe the answer is:
omens
'signs' is the definition.
(omen is a kind of sign)
'nothing and workers succeeded' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'and' means one lot of letters go next to another.
'workers' becomes 'men' (man is a kind of worker).
'succeeded' becomes 's' (genealogical abbreviation).
'o'+'men'+'s'='OMENS'
(Other definitions for omens that I've seen before include "Prognostications" , "Prophetic signs of good or evil" , "Signs or warnings for the future" , "Auguries" , "Harbingers, portents" .)