Irritates by crazy risk (4)
I believe the answer is:
irks
'irritates' is the definition.
The definition and answer can be both to do with human feelings as well as being verbs in their -s form.
Perhaps they are linked in a way I don't understand?
'crazy risk' is the wordplay.
'crazy' is an anagram indicator.
'risk' with letters rearranged gives 'IRKS'.
'by' acts as a link.
Can you help me to learn more?
(Other definitions for irks that I've seen before include "Annoys, vexes" , "'Irritate, annoy (4)'" , "Galls" , "Annoys, irritates" .)