Throws in (4)
I believe the answer is:
adds
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">throws in</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for adds that I've seen before include "Puts in; tacks on" , "Tots up" , "Puts (numbers) together" , "Appends or increases" , "Reckons" .)