A fellow lives for handsome youth (6)
I believe the answer is:
adonis
'handsome youth' is the definition.
(I've seen this before)
'a fellow lives' is the wordplay.
'fellow' becomes 'don' (both can mean an academic).
'lives' becomes 'is' ('be' can be a synonym of 'live').
'a'+'don'+'is'='ADONIS'
'for' acts as a link.
(Other definitions for adonis that I've seen before include "Extremely handsome young man" , "lovely man" , "Beautiful Greek youth" , "Said no to the Greek youth" , "Archetype of male beauty" .)