Don't take no for an answer (6)
I believe the answer is:
insist
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">don't take no for an answer</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for insist that I've seen before include "Be adamant" , "Be firm in demands" , "Continue to assert, maintain" , "Maintain firmly" , "Refuse to give way" .)