One or the other (6)
I believe the answer is:
either
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one or the other</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 either that I've seen before include "could be one of two" , "Word introducing first alternative" , "Her tie (anag.)" , "Each of two; moreover" , "offered a choice" .)