Fishermen avoiding large nettles (6)
I believe the answer is:
angers
'nettles' is the definition.
(I've seen this in another clue)
'fishermen avoiding large' is the wordplay.
'fishermen' becomes 'anglers' (angler is a kind of fisherman).
'avoiding' suggests deleting specific letters.
'large' becomes 'L' (eg in clothes sizes).
'anglers' with 'l' removed is 'ANGERS'.
(Other definitions for angers that I've seen before include "Irritates" , "Maine city" , "Riles" , "Maddens" , "Winds up" .)