annoyanceThe café was cash only, which was a minor annoyance as I only had my credit card with me.
inconvenienceThank you for holding - we apologize for the inconvenience.
irritationThe CEO's poor communication skills became a source of irritation to the company's investors.
irritantThe noise of the building work is a constant irritant.
boreinformalIt's such a bore to have to pack everything up again.
pain (in the neck)informalThat kid is such a pain in the neck.
botherUKIf it's a bother, we can do it another time.
pestinformalQuit being such a pest and leave me alone!