atheist
Americannoun
-
a person who does not believe in the existence of a supreme being or beings.
-
a person who believes that there is no supreme being or beings.
noun
adjective
Usage
What does atheist mean? An atheist is a person who does not believe in the existence of a supreme being or deity. In other words, an atheist is a person who does not believe in the existence of God or of any gods. The belief or doctrine that denies the existence of gods or supreme beings is atheism. Atheist can also be used as an adjective to describe such beliefs or things involving such beliefs. The adjective atheistic can be used in the same way. The word atheist means something different from the word agnostic, which refers to a person who believes it is impossible to know whether or not a supreme being exists. When asked if God or gods exist, an atheist would answer “No,” while an agnostic would answer “It is impossible to know.”Example: Being an atheist doesn’t mean I think God is bad—it means that I think God doesn’t exist.
Synonym Usage
See agnostic.
Other Word Forms
Derived Forms
Etymology
Origin of atheist
First recorded in 1565–75; from Greek áthe(os) “godless” + -ist; see a- 6 ( def. ), theo-
Explanation
An atheist believes there is no such thing as god, or any other deity. The root -theist means "belief in a god." The prefixes mono-, poly-, and a-, mean "one," "many," and "no," respectively. So a monotheist is someone who believes in a single god, a polytheist is someone who believes in many gods, and an atheist is someone who believes there is no god at all.
Vocabulary lists containing atheist
The Catcher in the Rye
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World Religions
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The Stranger
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Lou assumes her husband is an atheist and doesn’t understand when she discovers a Bible in the house.
From Los Angeles Times • Nov. 18, 2025
He describes himself as an atheist and said it felt like "a bit of an imposition and probably a bit unfair and silly".
From BBC • Nov. 17, 2025
The Chinese government remains officially atheist and keeps tight control over organized religion.
From Barron's • Nov. 1, 2025
Officially, the Communist Party is atheist, with the only legal churches in China being those sanctioned by the state.
From The Wall Street Journal • Oct. 12, 2025
It was held in a huge church, which seemed strange considering Kerry was an outspoken atheist, but that part I could understand.
From "If I Stay" by Gayle Forman
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
