Money reserve (4)
I believe the answer is:
fund
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">money reserve</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for fund that I've seen before include "Provide with money, say project" , "Finance" , "Cash reserve" , "Reserve of money set aside for a purpose" , "Sum of money set aside for a purpose" .)