Error allowance (6)
I believe the answer is:
margin
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">error allowance</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for margin that I've seen before include "Blank space that surrounds the text on a page" , "Bound" , "Edge; room for error" , "Blank space around the edge" , "Permissible difference" .)