Noun

(en noun)

Someone who, in the opinion of others, believes contrary to the fundamental tenets of a religion he claims to belong to.

* '>citation

In the framework of traditional medical ethics, the patient
deserves humane attention only insofar as he is potentially
healthy and is willing to be healthy—just as in the framework
of traditional Christian ethics, the heretic deserved humane
attention only insofar as he was potentially a true believer and
was willing to become one. In the one case, people are
accepted as human beings only because they might be healthy
citizens; in the other, only because they might be faithful
Christians. In short, neither was heresy formerly, nor is sick-
ness now, given the kind of humane recognition which, from
the point of view of an ethic of respect and tolerance, they
deserve.

Noun

(en noun)

(narrowly) A person who believes that no deities exist (qualifier).

* {{quote-book, date = 1571-10-20

, first = Arthur , last = Golding , chapter = The Epistle Dedicatory , title = Psalmes of Dauid and others, with M. 's Commentaries , url = http://www.sacred-texts.com/chr/calvin/cc08/cc08004.htm , passage = Ageine, the Atheistes , which say in their hartes there is no God; }}

* {{quote-magazine, date = 1953-11-03

, first = Bertrand , last = Russell , authorlink = Bertrand Russell , title = What is an Agnostic? , magazine = Look , url = http://scepsis.ru/eng/articles/id_5.php , passage = An atheist', like a Christian, holds that we ''can'' know whether or not there is a God. The Christian holds that we can know there is a God; the ' atheist , that we can know there is not. }}

(broadly) A person who rejects belief that any deities exist (whether or not that person believes that deities do not exist).

* {{quote-magazine, year = 1843

, title = A Reciprocal Dialogue , first = G. J. , last = Holyoake , authorlink = George Holyoake , editors = Paterson, Thomas , magazine = , volume = 2 , issue = 64 , page = 89 , url = http://books.google.com/books?id=1apbAAAAQAAJ&pg=PA89&dq=atheism , passage = Minister—Are you really an Atheist ?
Atheist—Yes.
M.—Do you deny that there is a god?
A.—No. I deny that there is sufficient reason to believe there is one. There may be a god, but I think it rather unlikely. }}

* {{quote-book, date = 2006-09-18

, first = Richard , last = Dawkins , title = The God Delusion , publisher = Houghton Mifflin , location = Boston , chapter = The God Hypothesis , page = 51 , edition = 1st Am. , isbn = 978-0618680009 , lccn = 2006015506 , id = , ol = 7606171M , url = http://books.google.com/books?id=yq1xDpicghkC&pg=PA73 , passage = Very low probability, but short of zero. De facto atheist . ‘I cannot know for certain but I think God is very improbable, and I live my life on the assumption that he is not there.’ }}

(loosely) A person who has no belief in any deities, such as a person who has no concept of deities.

* {{quote-book, year = 1772

, original = Le Bon-Sens, ou, Idées Naturelles opposées aux Idées Surnaturelles , by = , year_published = 2004 , title = Good Sense without God: Or Freethoughts Opposed to Supernatural Ideas , location = London , publisher = W. Stewart , section = §30 , page = 21 , url = http://books.google.com/books?id=vTqR5r1_DqYC&pg=PA21 , passage = All children are born Atheists ; they have no idea of God. Are they then criminal on account of their ignorance? }}

* {{quote-book, year = 1910

, title = The Vermont Digest 1789-1905 , publisher = Free Press Printing Co , location = Burlington , volume = 2 , url = http://books.google.com/books?id=HlgWAAAAYAAJ&pg=PR137 , passage = Atheists. One who does not believe in the existence of a Supreme Being, an atheist , is incompetent as a witness, being incapable of being sworn. [...] Changed by Acts of 1851, No. 12 (P. S. 1593), under which, no question can be raised as to a witness's "opinions on matters of religious belief." }}

(loosely, uncommon) A person who does not believe in a particular deity (or any deity in a particular pantheon), notwithstanding that they may believe in another deity.

* {{quote-book, year = 1840

, first = Edward , last = Gibbon , authorlink = Edward Gibbon , title = The Decline and Fall of the Roman Empire , edition = new , volume = 1 , chapter = 16 , page = 183 , passage = Malice and pejudice concurred in representing the christians(SIC) as a society of atheists , who, by the most daring attack on the religious constitution of the empire, had merited the severest animadversion of the civil magistrate. }}

* {{quote-video, year = 2002

, month = February , first = Richard , last = Dawkins , title = Richard Dawkins on militant atheism , work = TED , url = http://www.ted.com/talks/lang/eng/richard_dawkins_on_militant_atheism.html , passage = An atheist' is just somebody who feels about Yahweh the way any decent Christian feels about Thor or Baal or the golden calf. As has been said before, we are all ' atheists about most of the gods that humanity has ever believed in. Some of us just go one god further. }}