Sanction or advocate (7)
I believe the answer is:
endorse
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sanction</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that endorse is a more specific form of sanction)</span><br/ ><br/ >'<span class="explanation-format__original">advocate</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for endorse that I've seen before include "Back, sanction" , "Uphold" , "Ratify" , "Approve or underwrite" , "Add one's authority to" .)