Top revealed belt (8)
I believe the answer is:
outstrip
'top' is the definition.
(I know that top can be written as outstrip)
'revealed belt' is the wordplay.
'revealed' becomes 'out' (I've seen this in other clues).
'belt' becomes 'strip' (belt can mean a strip or bar of something).
'out'+'strip'='OUTSTRIP'
(Other definitions for outstrip that I've seen before include "Move faster than (someone else)" , "Leave behind" , "Move faster than and overtake" , "Go faster or do better than" , "Exceed in performance" .)