Decline swim (3)

I believe the answer is:

dip

I believe this is a double definition.

'decline' is the first definition.
(both can mean to fall or droop)

'swim' is the second definition.
(dip can mean a brief swim)

(Other definitions for dip that I've seen before include "A quick bathe" , "Thick sauce; brief swim" , "Sudden sharp decrease in quantity" , "Quick swim" , "Duck" .)

I've seen this clue in The Times.

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