Risks conclusions involving annoyance (9)
I believe the answer is:
endangers
'risks' is the definition.
(I've seen this before)
'conclusions involving annoyance' is the wordplay.
'conclusions' becomes 'ends' (end is a kind of conclusion).
'involving' means one lot of letters goes inside another.
'annoyance' becomes 'anger' (I've seen this before).
'ends' enclosing 'anger' is 'ENDANGERS'.
(Other definitions for endangers that I've seen before include "poses a threat" , "Places in peril" , "Puts in peril" , "Puts into jeopardy" , "Risks" .)