Establishment figure limiting student struggle (8)
I believe the answer is:
flounder
'struggle' is the definition.
(flounder can mean to struggle)
'establishment figure limiting student' is the wordplay.
'establishment figure' becomes 'founder' (someone who established something).
'limiting' indicates putting letters inside.
'student' becomes 'l' (as in L-plates for learner drivers).
'founder' going around 'l' is 'FLOUNDER'.
(Other definitions for flounder that I've seen before include "Fish; stagger clumsily" , "Struggle in water" , "fumble?" , "Fish -- stumble helplessly" , "thrash around wildly" .)