To do with marriage (7)
I believe the answer is:
marital
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">to do with marriage</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know this)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for marital that I've seen before include "Conjugal" , "Relating to marriage" , "Of nuptials" , "Relating to union of husband and wife" , "Connubial" .)