Threaten fisherman having thrown line on tip (8)
I believe the answer is:
endanger
'threaten fisherman' is the definition.
'endanger' can be an answer for 'threaten' (synonyms). I'm unsure of the 'fisherman' bit.
'thrown line on tip' is the wordplay.
'thrown line' becomes 'anger' (I am not sure about this - if you are sure you should believe this answer much more).
'on' means one lot of letters go next to another.
'tip' becomes 'end' (tip can mean the end of something).
'anger' put after 'end' is 'ENDANGER'.
'having' is the link.
Can you help me to learn more?
(Other definitions for endanger that I've seen before include "Pose a threat to" , "Expose to injury or extinction" , "Put in peril" , "Imperil" , "Put someone at risk" .)