Inadequate or deficient (12)
I believe the answer is:
insufficient
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">inadequate</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">deficient</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for insufficient that I've seen before include "Not enough" , "In short supply" .)