Improper, inappropriate (8)
I believe the answer is:
unseemly
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">improper</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">inappropriate</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for unseemly that I've seen before include "Unbecoming, not fitting" , "Unbecoming, impolite" , "Disreputable" , "Inappropriate" , "Indecent" .)