Kafir
Unbeliever. First applied to Meccans who refused submission to Islam, the term implies an active rejection of divine revelation. All unbelievers are thought to face eternal damnation in the afterlife. Although there is disagreement about whether Jews and Christians are unbelievers, they have generally received tolerant treatment from Muslim governments. Islamic fundamentalists in the twentieth century applied the term to other Muslims who did not adhere to their strict interpretations of the Quran.
See also Kufr