a pesky mosquito.
a plaguey newfangled safety catch.
a teasing and persistent thought annoyed him.
a vexatious child.
aircraft noise is particularly bothersome near the airport.
an irritating delay.
an irritative agent.
bites of black flies are more than irritating.
they can be very painful.
found it galling to have to ask permission.
it is vexing to have to admit you are wrong.
nettlesome paperwork.
swarms of pestering gnats.
tapping an annoying rhythm on his glass with his fork.