Pam's swimming in some current (4)
I believe the answer is:
amps
'some current' is the definition.
(I've seen this before)
'pam's swimming' is the wordplay.
'swimming' is an anagram indicator (letters swim around into a new order).
'pams' anagrammed gives 'AMPS'.
'in' is the link.
(Other definitions for amps that I've seen before include "Current measures" , "Basic units of electric current" , "concert gear" , "'Units of electric current, in short (4)'" , "Spam (anag)" .)