An academic lives for handsome youth (6)
I believe the answer is:
adonis
'handsome youth' is the definition.
(I've seen this before)
'an academic lives' is the wordplay.
'an' becomes 'a'.
'academic' becomes 'don' (type of academic - especially at Oxbridge).
'lives' becomes 'is' ('be' can be a synonym of 'live').
'a'+'don'+'is'='ADONIS'
'for' is the link.
(Other definitions for adonis that I've seen before include "Most 8 Greek youth" , "Fit bloke" , "Beautiful young man" , "lovely man" , "male looker" .)