Swirl (4)
I believe the answer is:
eddy
'swirl' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for eddy that I've seen before include "movement going round in circles" , "She founded Christian Science in 1866, d. 1910" , "Christian Scientist" , "Current running against the main stream, causes small whirlpool" , "dangerous bit of water" .)