Tidal flood (4)
I believe the answer is:
bore
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tidal flood</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 bore that I've seen before include "Fast-running water" , "Drill - pest" , "Tedious person; steep wave" , "Diameter of a gun barrel" , "Suffered" .)