Snarl up the net badly that you fish with (8)
I believe the answer is:
entangle
'snarl up' is the definition.
(thesaurus)
'the net badly that you fish with' is the wordplay.
I cannot really understand how this works, but
an anagram of 'net' is 'ent' which is present in the answer.
'fish' could be 'angle' (angling is a kind of fishing) and 'angle' is found in the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for entangle that I've seen before include "Twist together into a confusing mass" , "Ensnare" , "Ravel" , "Create confusion" , "snarl" .)