Caboose's location (4)
I believe the answer is:
rear
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">caboose's location</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 rear that I've seen before include "Bring up - back end" , "Bring up (children)" , "early, long before now" , "Raise - back" , "what you may bring up" .)