Fellow arts graduates I left (5)
I believe the answer is:
basil
'fellow' is the definition.
(I've seen this before)
'arts graduates i left' is the wordplay.
'arts graduates' becomes 'BAs' (people with Bachelor of Arts degrees).
'left' becomes 'l' (common abbreviation).
'bas'+'i'+'l'='BASIL'
(Other definitions for basil that I've seen before include "named Cardinal Hume" , "Herb (from Fawlty Towers?)" , "Sweet-smelling herb" , "Culinary plant" , "Herb of mint family" .)