Get the wrong idea (13)
I believe the answer is:
misunderstand
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">get the wrong idea</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 misunderstand that I've seen before include "Fail to comprehend" , "Make little of" , "Fail to construe correctly" , "Fail to interpret correctly" , "Interpret wrongly" .)