Top of a building (4)
I believe the answer is:
roof
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">top of a building</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for roof that I've seen before include "Upper limit; house top" , "hit by someone in a temper" , "Top outside covering" , "Top of car/house" , "See 24" .)