Student with ace material (4)
I believe the answer is:
lace
'material' is the definition.
(lace is a kind of material)
'student with ace' is the wordplay.
'student' becomes 'l'.
'with' says to put letters next to each other.
'l'+'ace'='LACE'
(Other definitions for lace that I've seen before include "Delicate open-weave fabric" , "Delicate open-web fabric" , "Famous play ''Arsenic and Old . . . .''" , "A fabric; add alcohol to" , "Shoe string" .)