4 Answers

Anyone who does not believe in the Muslim God according to the Muslims. This works for Christianity too (see Kings James version). All the other versions have since changed "infidel" to "unbelievers". Still means the same, they just tried to go p.c. with it.

     "Infidel" means "one without faith", referring to someone who has no belief in religion.  It's used by Christians to refer to atheists as well as, Colleen has mentioned, those who reject Islam.

I withdrew my faith in belief because I wanted to know God better and beliefs are loaded with opinions that are sustained by faith. This formula locks  a person into their view of faith related subjects. By revoking my beliefs my awareness  of God became a living fact of association and presence that is not modified or obstructed. When I had beliefs my relationship with God was like talking through a veil…unsure who or what was on the other side of that veil. Now I know and I won’t hide behind that veil again. 

A normal human. Not a muslim.