Fishhook's end (4)
I believe the answer is:
barb
'fishhook's end' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for barb that I've seen before include "A thorn or a gibe" , "nasty comment" , "Aggressive remark directed at a person" , "Small prong on larger point" , "Jibe" .)