That's one in the eye for scholar (5)
I believe the answer is:
pupil
I believe this is a double definition.
'that's one in the eye' is the first definition.
('pupil' is part of 'eye')
'for scholar' is the second definition.
(pupil is a kind of scholar)
(Other definitions for pupil that I've seen before include "One being taught" , "Aperture in an eye" , "School learner" , "Trainee barrister" , "bit of a looker" .)