Ensign; flag (6)
I believe the answer is:
banner
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">ensign</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">flag</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that banner is a type of flag)</span><br/ ><br/ ></span>
(Other definitions for banner that I've seen before include "One not allowing" , "Military standard" , "Pennant" , "Web page header; flag" , "Prohibitionist - flag" .)