Dead bird a student finds outside? (8)
I believe the answer is:
external
'outside?' is the definition.
('external' can be a synonym of 'outside')
'dead bird a student' is the wordplay.
'dead' becomes 'ex' (prefix meaning former or onetime).
'bird' becomes 'tern' (tern is a kind of bird).
'student' becomes 'l' (as in L-plates for learner drivers).
'ex'+'tern'+'a'+'l'='EXTERNAL'
'finds' acts as a link.
(Other definitions for external that I've seen before include "Coming from outside" , "Belonging to the outside" , "abroad" , "Outward" , "involving foreign nations" .)