Not true to allegiance, duty, or vows
Lacking faith; lacking belief in something.
Unfaithful (said of people, towards their partners)
Not believing in God, religion, or a comparable ideology.
Serving to disappoint or deceive
Not observant of promises or covenants.
Having or demonstrating undivided and constant support for someone or something.
Firm in allegiance to a person or institution.
Faithful to a person or cause.