I didn't tell anybody they are not anything.<quoted text>
Except, of course, when you're telling us that we're not atheists.
Some even have more than one meaning.
That is discovered by observing how people use the word, not by dictatorial sources trying to control that usage.
Speaking of word meanings, are you aware of the difference between the words "descriptive" and "prescriptive" in the context of lexicography? If not, allow me: Descriptive lexicography refers to the creating dictionaries according to how people actually write and speak, whereas prescriptive lexicography refers to trying to limit people's usage to conform to that of some private agenda.
I am an atheist because having rejected all god claims, I live without theism. I'm also an aleprechaunist and an avampirist, but the issue doesn't come up as often given the relatively small number of leprechaunists and an vampirists compared to theists.
Of course the rejection of god claims is rational. There is no other rational position possible until compelling evidence for a god is produced. Without that, there is no rebuttal to atheism.
I did tell somebody that if they choose a term for themselves, they should know what it means. I also told them that if what they believe does not fit the meaning of a particular term, instead of attempting to change the meaning of the term, they should choose a different term, preferably one that fits.
This is why the meaning of words is important - because your misunderstanding of a term just then caused you to mischaracterize the debate surrounding it.
"Atheism" is not subject to rebuttal, nor is theism.
Atheism and theism are not claims. They are beliefs, which means they are a conclusion held by the experiencer which supercedes what is knowable.
On the other hand, if a factual claim is made that no god exists, it is subject to rebuttal. The belief that no god exists is not.