Held in common (6)
I believe the answer is:
mutual
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">held in common</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 mutual that I've seen before include "Dickens novel 'Our . . . . . . Friend'" , "Reciprocal or shared, like friendship" , "Common to two or more" , "building society, say" , "Reciprocal; common" .)