Irritates by generating risk (4)
I believe the answer is:
irks
'irritates' is the definition.
(I've seen this in another clue)
'generating risk' is the wordplay.
'generating' indicates an anagram (I've seen 'generated' mean this).
'risk' is an anagram of 'IRKS'.
'by' is the link.
(Other definitions for irks that I've seen before include "Annoys, vexes" , "Annoys, irritates" , "'Irritate, annoy (4)'" , "Galls" .)