Top of the heap (4)
I believe the answer is:
best
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">top of the heap</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 best that I've seen before include "George -, footballer" , "unbeatable" , "The finest - worst" , "Overcome" , "Worst -- as good as can be" .)