Swirl, whirl (4)
I believe the answer is:
eddy
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">swirl</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">whirl</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for eddy that I've seen before include "religious leader" , "movement going round in circles" , "Turner at sea" , "current running back" , "Spin" .)