Fifty making a living by scholarship (8)
I believe the answer is:
learning
'scholarship' is the definition.
(I know that scholarship can be written as learning)
'fifty making a living by' is the wordplay.
'fifty' becomes 'l' (Roman numeral).
'making a living' becomes 'earning' (I've seen this in another clue).
'by' means one lot of letters go next to another.
'l'+'earning'='LEARNING'
(Other definitions for learning that I've seen before include "Researching - scholarship" , "Erudition - education" , "(Knowledge from) study" , "Acquired knowledge" , "Lore" .)