Threatening, ominous (8)
I believe the answer is:
menacing
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">threatening</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that threatening can be written as menacing)</span><br/ ><br/ >'<span class="explanation-format__original">ominous</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that ominous can be written as menacing)</span><br/ ><br/ ></span>
(Other definitions for menacing that I've seen before include "Ominous" , "Threatening" , "Suggesting danger" , "Intimidating" , "Scary" .)