Asset (4)
I believe the answer is:
plus
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">asset</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that asset can be written as plus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for plus that I've seen before include "asset" , "As well as" , "Something more" , "Added extra" , "sign of the cross" .)