Twosome, couple (4)
I believe the answer is:
pair
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">twosome</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that twosome can be written as pair)</span><br/ ><br/ >'<span class="explanation-format__original">couple</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that couple can be written as pair)</span><br/ ><br/ ></span>
(Other definitions for pair that I've seen before include "players of duet?" , "Agreement to avoid division" , "Brace, couple" , "Duo" , "Husband and wife" .)