Knee-cap (7)
I believe the answer is:
patella
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">knee-cap</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 patella that I've seen before include "showing a bit of leg" , "bit of body usually under trousers!" , "positioned on each knee" , "Kneecap (anatomy)" , "Knee bone" .)