Paris subway (5)
I believe the answer is:
metro
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">paris subway</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 metro that I've seen before include "Parisian underground system" , "Paris subway" , "The Paris Underground transport system" , "Paris underground rail system" , "Urban railway system" .)