Stir if leak reveals loot (5)
I believe the answer is:
rifle
'loot' is the definition.
(thesaurus)
'stir if leak reveals' is the wordplay.
'reveals' indicates a hidden word.
'RIFLE' is hidden in the letters of 'stir if leak'.
(Other definitions for rifle that I've seen before include "Go through in search" , "Gun; plunder" , "Flier (anag.)" , "Gun - ransack" , "Standard military gun fired from shoulder" .)