Stable; poised (8)
I believe the answer is:
balanced
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">stable</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">poised</span>' is the second definition.<br/ ><span class="explanation-format__explanation">('balance' can be a synonym of 'poise')</span><br/ ><br/ ></span>
(Other definitions for balanced that I've seen before include "Equipoised" , "With weight evenly distributed, or equalised" , "Having weight equally distributed" , "Steady - objective" , "Having different elements in the correct proportions, in a diet say" .)