XI (6)
I believe the answer is:
eleven
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">xi</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for eleven that I've seen before include "Time for the mid-morning tea break?" , "XI as Roman numeral" , "Bingo's "legs"?" , "Lowest two-digit prime" , "Players" .)