Falsify (9)
I believe the answer is:
fabricate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">falsify</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fabricate that I've seen before include "forge" , "Make up; manufacture" , "Invent, make up" , "Construct or invent" , "Tell lies" .)