False belief (7)
I believe the answer is:
fallacy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">false belief</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for fallacy that I've seen before include "'Misconception, false belief (7)'" , "Faulty reasoning or mistaken belief" , "A mistake in reasoning" , "False or mistaken belief." , "Delusion" .)