Liter or meter (4)
I believe the answer is:
unit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">liter or meter</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 unit that I've seen before include "Small group" , "Part of a kit" , "One; military group" , "Military team" , "hospital department" .)