Lying down (5)
I believe the answer is:
prone
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">lying down</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 prone that I've seen before include "Lying flat" , "Prostrate" , "Lying face down or likely to do something" , "Showing a tendency" , "Liable (to suffer) - lying down" .)