Bar them, briefly from swim (5)
I believe the answer is:
bathe
'swim' is the definition.
(bathe can mean to swim)
'bar them briefly' is the wordplay.
'bar' becomes 'ba' (I can't explain this - if you can you should believe this answer much more).
'briefly' means to remove the last letter.
'them' with its last letter removed is 'the'.
'ba'+'the'='BATHE'
'from' is the link.
Can you help me to learn more?
(Other definitions for bathe that I've seen before include "Swim or paddle" , "Take a swim; envelop" , "Wash in water" , "Swim in sea" , "Immerse in liquid for wash" .)