US-Canadian falls (7)
I believe the answer is:
niagara
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">us-canadian falls</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 niagara that I've seen before include "North American waterfall" , "Famous waterfalls" , "N. American waterfall" , "Great waterfalls on border of USA and Canada" , "A lot of falling water" .)