grievance

Short definition from Wiktionary

Noun

1. 1
   Something which causes grief.
2. 2
   A wrong or hardship suffered, which is the grounds of a complaint.
3. 3
   Feelings of being wronged; outrage; resentment, bitterness or anger.
4. 4
   A complaint or annoyance.
5. 5
   A formal complaint, especially in the context of a unionized workplace.
6. 6
   Violation of regulations or objectionable behavior.