Swine from E Devon waterway? (6)
I believe the answer is:
rotter
'swine' is the definition.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for rotter that I've seen before include "Absolute bounder" , "Scoundrel" , "Despicable person" , "Cad, bounder" , "Bad guy" .)