Accept as true without proof (6)
I believe the answer is:
assume
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">accept as true without proof</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for assume that I've seen before include "Adopt falsely" , "Adopt or take for granted" , "Suppose; put on" , "Take as true or take for granted" , "Take as true without proof" .)