infidel

An unbeliever with respect to a particular religion, especially Christianity or Islam.

One who has no religious beliefs.

One who doubts or rejects a particular doctrine, system, or principle.

Without faith: unbelieving; disbelieving; especially, rejecting the distinctive doctrines of a particular religion, while perhaps an adherent of some other religion.

Specifically Rejecting the Christian religion while accepting no other; not believing in the Bible or any divine revelation: used especially of persons belonging to Christian communities.

Due to or manifesting unbelief.

An unbeliever; a disbeliever; one who denies the distinctive tenets of a particular religion.

Specifically A disbeliever in religion or divine revelation in general; especially, one who denies or refuses to believe in the Christian religion while accepting no other; one who rejects the inspiration of the Scriptures, or the divine origin and authority of Christianity as revealed in the Bible.

In feudal law, one who violated fealty. Rapalje and Lawrence.

One who does not believe in the prevailing religious faith; a heathen; a freethinker; — used especially by Christians and Mohammedans.