Partner in marriage (6)
I believe the answer is:
spouse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">partner in marriage</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for spouse that I've seen before include "Married partner" , "Consort" , "mate" , "Elizabethan dance" , "Possibly wife" .)