To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement.
Hopefully; a self-directive to undertake the customary action to ward off bad luck.
To reproach, blame; to ridicule or tease.
To ignore or killfile (a user on a bulletin board system).
A foolish or annoying person.
A reproach, gibe or taunt.
A person who twitters, i.e. chatters inanely.