Fine by me, since it affects what I think not one whit.
The point is that a communicative consensus does not mean I must take your definitions, nor even that these definitions must be decided upon before hand. Whenever I am involved in a technical discussion about anything at work, one of the most common questions is "What do you mean by X?"
As everyone in the room has both similar skill-sets and work in the same business, you'd think that what 'X' means would be fairly clear. But as I have just spent the whole day rewriting a bunch of margin calculations because when someone said one cost they actually meant another, this is hardly a given. Sometimes, in order to communicate, it is necessary to ask.
If I wish to communicate with you, you might feel it right that I use your definitions, or at least distinguish mine from yours to avoid confusion. We could, for example, say you are an 'orthodox atheist' (strictly requiring no belief in gods) and I am a 'liberal atheist' (more loosely requiring no ceding of influence to one), though that has some bad connotations. Or you might insist that I mustn't refer to what I believe as atheism, in which case I may decide to call it 'athriscism' meaning without religion (probably, I haven't done any A.Greek since the 80s, so forgive me if I f***ed up), or I may decide not to communicate with you at all.
Similarly, if you wish to communicate with me, why shouldn't I insist on using my definitions? Perhaps, referring to yours as 'adoxotheism' (without belief in gods(?)) to distinguish it from all the other ways someone could be without god which I might recognise.
In fact, my atheism and yours will largely coincide since I do not believe in gods either (or any supernatural phenomena, come to that), and you can most probably accommodate my beliefs with little trouble, as I suspect I can accomodate yours; where we may diverge is how we view a third person's beliefs. However, I try to be tolerant of other's beliefs (not necessarily their actions), and that extends to what they wish to call them. There can be no "freedom of belief" if you allow only particular definitions of a particular belief to go by that name. Otherwise why not define "Christian" to mean Baptists and no-one else? (They'd love that!) Or Muslim to mean Sunni? Or Buddhism to exclude Theravada?
I will believe what I want, and call myself atheist (since, in my opinion, that is what I am), so I can hardly deny anyone else the right to do the same. I will, no doubt, have an opinion on what they do or do not believe, but that's all it is.
I am not going to condemn an 'atheist' for believing in God (as innumerable people did on publication of the last Pew report), though I may be more than a little curious as to what he means by 'atheism'. After all, if I wish people to be tolerant of my beliefs, should I not be tolerant of theirs[*]?
[* Again 'beliefs' not 'actions'. I often see arguments to the effect, "I want to remove your rights and you are saying I can't, you're intolerant!", which A.C.Grayling framed this as 'tolerance defending itself' (after Montesque), arguing that the tolerant should tolerate everything except intolerance. I'm perhaps a bit laxer in that I usually tolerate people talking intolerantly, but not trying to organise or systematise intolerance. So saying "Whites rule!" is reprehensible but allowed, trying to have all non-whites disenfranchised is reprehensible and not.
On the whole, I try to meet tolerance with tolerance. So I might treat someone believing in the rapture with derision (as I'm sure they treat my views) and save my anger for people who believe atheists shouldn't be allowed citizenship, children, votes, to breathe, etc.]
