The best stuff around the East (5)
I believe the answer is:
cream
'the best' is the definition.
(as in 'the cream of the crop')
'stuff around the east' is the wordplay.
'stuff' becomes 'cram' (cramming is a kind of stuffing).
'around' indicates putting letters inside.
'the east' becomes 'E' (synonyms).
'cram' enclosing 'e' is 'CREAM'.
(Other definitions for cream that I've seen before include "It rises to the top, the best" , "treat for cat?" , "Best - ointment" , "Pick - fatty part of milk" , "Elite; pale yellow" .)