It's really "Kafir" which is somewhat translated as "Infidel" but is is what's considered infidel by most."
1. Religion .
a. a person who does not accept a particular faith, especially Christianity.
b. (in Christian use) an unbeliever, especially a Muslim.
c. (in Muslim use) a person who does not accept the Islamic faith; kaffir.
2. a person who has no religious faith; unbeliever.
3. (loosely) a person who disbelieves or doubts a particular theory, belief, creed, etc.; skeptic. adjective
4. not accepting a particular faith, especially Christianity or Islam; heathen.
5. without religious faith.
6. due to or manifesting unbelief: infidel ideas.
7. rejecting the Christian religion while accepting no other; not believing in the Bible or any Christian divine revelation.
8. Also, in•fi•del•ic [in-fi-del-ik] Show IPA . of, pertaining to, or characteristic of unbelievers or infidels.
Kafir:
http://en.wikipedia.org/wiki/Kafir
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