Central American waterway (6,5)
I believe the answer is:
panama canal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">central american waterway</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 panama canal that I've seen before include "Busy waterway" , "Pacific-Caribbean link" , "Central American waterway" , "Atlantic/Pacific waterway" , "Waterway link" .)