Strong resentment about lake fisherman (6)
I believe the answer is:
angler
'lake fisherman' is the definition.
'angler' can be an answer for 'fisherman' (angler is a kind of fisherman). I am not certain of the 'lake' bit.
'strong resentment about' is the wordplay.
'strong' becomes 'l' (I can't justify this - if you can you should give a lot more credence to this answer).
'resentment' becomes 'anger' (I've seen this in another clue).
'about' is an insertion indicator.
'l' placed into 'anger' is 'ANGLER'.
Can you help me to learn more?
(Other definitions for angler that I've seen before include "who looks for compliments" , "A rod and line fisherman" , "Walton's was Compleat" , "One proverbially exaggerating" , "Fisher with hook and line." .)