a person who holds that the existence of the ultimate cause, as God, and the essential nature of things are unknown and unknowable, or that human knowledge ...
a person who does not have a definite belief about whether God exists or not. : a person who does not believe or is unsure of something. Source: ...
a person who believes that nothing is known or can be kno... Meaning, pronunciation, example sentences, and more from Oxford Dictionaries.
An atheist lacks faith in God, believes there is no god, or lacks awareness of gods