Defining "Atheism"

[Existentialist]

Amoral is not a denial of morality, it is a lack of morality.
Asexual is not a denial of sexuality, it is a lack of sexuality.
Atheism is not a denial of theism, it is a lack of theism.

Of course, the denial of theism is an atheistic position, but it is still atheism without that denial. That being the case, the only thing required to be defined as 'atheism' is a lack of belief in gods. The belief that there are no gods is not required to fit the definition of atheism.

That's why people use qualifiers to define their atheism more specifically. Denial of theism would require the qualifier 'strong' or possibly 'gnostic'. Without those qualifiers, the only thing the word atheism tells us is that the person does not believe in gods, not whether that person believes there are none.

I agree there is confusion between two separate and distinct definitions of atheism but I don't think it can be sorted out just by identifying the lowest common denominator between the two definitions. The most popular definition seems to be the one that says atheism is the denial of the existence of god. The problem is, if that gets watered down so that it gets included in the other definition, then what's the point of having a separate definition for it? Is there some dictionary rule about not being allowed to select one definition while rejecting the other? The site rules of this forum don't cover it, because if I say that atheism means the denial of the existence of god, but I don't think it means mere disbelief in god, then I'm still using a standard dictionary definition, I'm just not using all the definitions. Besides, it's not a problem because, as you say, the thread is about discussing what the meaning is.

I don't think most people have a clue what the qualifiers 'strong' and 'gnostic' mean. I can't honestly go round calling myself one of the gnostic atheists in general conversation, I understand it has a technical meaning, it just sounds like an obscure sect. I think that would be a cause for as much hilarity about my choice of words as I get from trying to describe meanings better in this site. I am really between the devil and the deep blue sea, I suppose.

I think your statements about amorality, asexuality and atheism are bad examples. Firstly as for as I can gather, a- is a generalised greek negative, not specifically 'lack of'. Second, it has come to mean different things when applied to different words. Thirdly, denial of the existence of god is specifically a dictionary definition - in fact, it's the most popular, so your three examples collapse as a proof of consistency. You can say denial of is encapsulated by lack of, but you can't really lay the law down an force a god-denier to accept the secondary definition, especially as he has already accepted the first.