The most common and most likely answer to this crossword clue is the 8 letter word FLY-FISH
I've seen this crossword clue in Independent
F
L
Y
-
F
I
S
H
Buddy explains!

The straight part
We know that "angle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case angle = fly-fish.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FLY-FISH mean?
FLY-FISH verb- To fish using a fly (fishing lure) as bait.