Riot spray (4)
I believe the answer is:
mace
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">riot spray</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for mace that I've seen before include "Spice; ceremonial baton" , "put on the rack?" , "Ceremonial staff or kind of spice" , "Ceremonial staff of office" , "Disabling spray" .)