Fortuitous (10)
I believe the answer is:
accidental
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fortuitous</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for accidental that I've seen before include "Happening by chance" , "Possible sharp" , "Subsidiary" , "Unintentional" , "Casual" .)