Abrasive gallery remembers revolutionary exhibits (5)
I believe the answer is:
emery
'abrasive' is the definition.
(I've seen this before)
'gallery remembers revolutionary exhibits' is the wordplay.
'exhibits' says the answer is hidden in the clue.
'revolutionary' says the letters should be written backwards.
'yreme' is hidden in the letters of 'gallery remembers'.
'yreme' in reverse letter order is 'EMERY'.
(Other definitions for emery that I've seen before include "Black abrasive" , "Hard, grey-black mineral used as 11 down" , "Rock used as abrasive" , "Coating on paper used as an abrasive" , "Abrasive material" .)