Alert, vigilant (7)
I believe the answer is:
wakeful
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">alert</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">vigilant</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that vigilant can be written as wakeful)</span><br/ ><br/ ></span>
(Other definitions for wakeful that I've seen before include "Not sleepy" , "Alert, vigilant" , "Not getting off" , "Unable to sleep" .)