Student left breadwinner (7)
I believe the answer is:
learner
'student' is the definition.
(thesaurus)
'left breadwinner' is the wordplay.
'left' becomes 'l' (common abbreviation).
'breadwinner' becomes 'earner' (I've seen this before).
'l'+'earner'='LEARNER'
(Other definitions for learner that I've seen before include "Novice driver" , "Disciple" , "New 17 across" , "One gaining knowledge" , "Acquirer of knowledge" .)