Sportsman showing displeasure when lake is filled in (6)
I believe the answer is:
angler
'sportsman' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for angler that I've seen before include "who looks for compliments" , "He fishes with rod and line" , "person hoping to catch fish" , "I may do casting" , "Fisher with rod and line" .)