Natural satellite of a planet (4)
I believe the answer is:
moon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">natural satellite of a planet</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for moon that I've seen before include "Show Bottom!" , "Where Armstrong stood" , "down one's pants" , "Appear listless" , "Remove boxers, maybe" .)