Something to take when you go swimming? (6)
I believe the answer is:
plunge
'swimming?' is the definition.
(I know that plunge is a type of diving)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for plunge that I've seen before include "Take the . . . . . . - jump right in" , "Jump or dive into water" , "Thrust into liquid" , "Sudden fall" , "Move suddenly" .)