Wait in line (5)
I believe the answer is:
queue
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wait in line</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for queue that I've seen before include "Line of people waiting for something" , "Tailback" , "Wait in line" , "Waiting list" , "Pigtail; get in line" .)