անհավատ

Etymology
From.

Adjective

 * 1) disbelieving, not believing in something
 * 2) faithless, lacking faith in religion or God
 * 3) infidel, not holding the faith of a given religion
 * 4)  untrustworthy
 * 5)  heartless, cruel

Noun

 * 1) disbeliever, a nonreligious person
 * 2) infidel, unbeliever