Very tall building (10)
I believe the answer is:
skyscraper
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">very tall building</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 skyscraper that I've seen before include "it's big in America?" , "multi-storey building" , "High-rise building?" , "Very high building" , "UN HQ building, say" .)