John Hancock (9)
I believe the answer is:
signature
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">john hancock</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 signature that I've seen before include "Handwritten name" , "proof of identity" , "One's mark" , "Personal mark" , "distinctive style" .)