Proper, fitting (6)
I believe the answer is:
seemly
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">proper</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">fitting</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for seemly that I've seen before include "Appropriate" , "Decent - handsome" , "Fitting" , "Decorous or proper" , "Decorous, in good taste" .)