1. (n.) One faithless to principle or party.

2. (n.) An apostate from Christianity or from any form of religious faith.

3. (n.) One who deserts from a military or naval post; a deserter.

4. (n.) A common vagabond; a worthless or wicked fellow.

Sabbath-breaker apostate apostatize atheist atheistic backslider backsliding blasphemer blasphemous bolter collaborationist collaborative collaborator convert defect defector degenerate desert deserter disloyal faithless fallen fallen from grace fifth columnist heretic heretical iconoclast impious insurgent irreligious irreverent lapsed mugwump perfidious profanatory profane proselyte quisling rat rebel recidivist recidivistic recreant renegado renegate renege reversionist runagate sacrilegious sacrilegist schismatic seceder secessionist separatist strikebreaker tergiversant tergiversating tergiversator traitor traitorous treacherous treasonable treasonous turn against turn traitor turnabout turncoat turntail unbeliever undutiful