When last word comes up, worker becomes hopeful (8)
I believe the answer is:
aspirant
'hopeful' is the definition.
(synonyms)
'when last word comes up worker' is the wordplay.
'when' becomes 'as'.
'last word' becomes 'rip' (I can't explain this - if you can you should give a lot more credence to this answer).
'comes up' says the letters should be written in reverse.
'worker' becomes 'ant' (worker is a type of ant).
'rip' backwards is 'pir'.
'as'+'pir'+'ant'='ASPIRANT'
'becomes' is the link.
Can you help me to learn more?
(Other definitions for aspirant that I've seen before include "Partisan (anag)" , "One hoping to succeed" , "Partisan sort of hopeful" , "Hopeful, wannabe" , "One seeking eg promotion" .)