UNBELIEVER
Etymology
Noun
unbeliever (plural unbelievers)
One who does not believe, particularly in a deity (used by believers to describe other people)
Synonyms
• infidel
• non-believer
• nonbeliever
Source: Wiktionary
Un`be*liev"er, n.
1. One who does not believe; an incredulous person; a doubter; a
skeptic.
2. A disbeliever; especially, one who does not believe that the Bible
is a divine revelation, and holds that Christ was neither a divine
nor a supernatural person; an infidel; a freethinker.
Syn.
– See Infidel.
Source: Webster’s Unabridged Dictionary 1913 Edition