Altogether, wholly (7)
I believe the answer is:
totally
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">altogether</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">wholly</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for totally that I've seen before include "Quite" , "Altogether" , "To the full extent" , "perfectly" , "Utterly" .)