Scot's swimming spot (4)
I believe the answer is:
loch
'scot's swimming spot' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for loch that I've seen before include "A Scottish lake like Ness" , "Ness or Lomond, for instance" , "A Scottish lake like Lomond" , "Scottish or Irish lake" , "Eg, Ness" .)