The compleat sportsman? (6)
I believe the answer is:
angler
'sportsman?' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for angler that I've seen before include "Fisher with hook and line." , "Strait; -- of Lochalsh" , "A rod and line fisherman" , "Sportsman" , "Isaac Walton wrote of the 'Compleat' one" .)