Unaware or forgetful (9)
I believe the answer is:
oblivious
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">unaware</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">forgetful</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that forgetful can be written as oblivious)</span><br/ ><br/ ></span>
(Other definitions for oblivious that I've seen before include "Forgetful; unaware" , "Unconscious" , "Absent-mindedly unaware" , "Blind (to)" , "Apt to forget" .)