Crossword Genius

Something to take when you go swimming? (6)

Ross

I believe the answer is:

plunge

I'm a little stuck... Click here to teach me more about this clue!

'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" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app