Very; in addition (3)
I believe the answer is:
too
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">very</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">in addition</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for too that I've seen before include "On top - also" , "Moreover, in addition" , "What a pity!" , "To a greater than desirable extent" , "Furthermore" .)