A recidivist; one who backslides, especially in a religious sense; an apostate.
She married him thinking to change his ways, and for a while he got religion, but he was ever a backslider; she soon began finding bottles stashed about the house.
A person or group that does not show up.
An absence; failure to show up or to make a scheduled appearance, especially at a hotel or a place of employment.
To fail to show up for something.