Student trapped by crude chance (7)
I believe the answer is:
earthly
'chance' is the definition.
(I've seen this before)
'student trapped by crude' is the wordplay.
'student' becomes 'l'.
'trapped by' indicates putting letters inside.
'crude' becomes 'earthy' (I've seen this before).
'l' going into 'earthy' is 'EARTHLY'.
(Other definitions for earthly that I've seen before include "a hopeless person doesn't have" , "Material; worldly" , "Chance (colloquial)" , "Relating to material things" , "No such possible chance" .)