Lucrative work student left out (6)
I believe the answer is:
earner
'lucrative work' is the definition.
(way of earning money)
'student left out' is the wordplay.
'student' becomes 'learner' (I've seen this before).
'left' becomes 'l' (common abbreviation).
'out' is a deletion indicator.
'learner' with 'l' removed is 'EARNER'.
(Other definitions for earner that I've seen before include "One who gets money for work" , "One bringing in wage" , "Good job" , "Something that makes a profit" , "Cash job" .)