Feeling of resentment or irritation (5)
I believe the answer is:
pique
I believe this is a double definition.
'feeling of resentment' is the first definition.
(I've seen this before)
'irritation' is the second definition.
(I know that irritation can be written as pique)
(Other definitions for pique that I've seen before include "Ill-feeling; fabric" , "Resentful feeling" , "Stimulate (one's curiosity)" , "Resentment; hurt pride" , "Show of annoyance" .)