Catch fish after net's torn (8)
I believe the answer is:
entangle
'catch' is the definition.
(I've seen this before)
'fish after net's torn' is the wordplay.
'fish' becomes 'angle' (angle can mean to fish).
'after' means one lot of letters go next to another.
'torn' indicates anagramming the letters.
'net' anagrammed gives 'ent'.
'angle' after 'ent' is 'ENTANGLE'.
(Other definitions for entangle that I've seen before include "Make twisted" , "Prize cup" , "Ravel" , "Involve in complications" , "caught up" .)