Unstable, shaky (8)
I believe the answer is:
insecure
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">unstable</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">shaky</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ ></span>
(Other definitions for insecure that I've seen before include "open to attack" , "(Feeling) unsafe" , "Timid" , "Not adequately protected" , "Not firmly fixed" .)