Boundaries (6)
I believe the answer is:
limits
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">boundaries</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know this)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for limits that I've seen before include "'Boundaries, demarcation lines (6)'" , "Bounds beyond which one cannot go" , "Boundaries, confines" , "Biblical prophet" , "Boundaries or furthest reaches" .)