Assume as a fact (5)
I believe the answer is:
posit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">assume as a fact</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for posit that I've seen before include "advance" , "Suppose" , "Put forward (argument)" , "Lay down as principle" , "Propose" .)