Studies top of exquisite compact (5)
I believe the answer is:
dense
'compact' is the definition.
('dense' can be a synonym of 'compact')
'studies top of exquisite' is the wordplay.
'studies' becomes 'dens' (I've seen this before).
'top of' says to take the initial letters.
The initial letter of 'exquisite' is 'e'.
'dens'+'e'='DENSE'
(Other definitions for dense that I've seen before include "Closely-spaced" , "Close-packed" , "Tightly packed - stupid" , "Compressed - obtuse" , "Closely spaced or extremely stupid" .)