Eddy (9)
I believe the answer is:
whirlpool
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eddy</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that eddy can be written as whirlpool)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for whirlpool that I've seen before include "Quickly rotating mass of water" , "Violent circular eddy of water" , "Strong circular current" , "Powerful circular current of water" .)