"Lack"

[Tiberius]

The definitions do range a little, which is why I think this sums it up quite well:

Anyone who answers the question "Do you believe in God" in anything but the positive is an atheist.[quote]
By that sampling you include both people who say no and "I don't know" (knowing is of course different from belief but some people simply don't understand that)

[quote='Kyuuketsuki' pid='3757' dateline='1226238993']
This may be of relevance (http://www.thedivineconspiracy.org/athart3.htm), haven't read it through yet but it seems to be suggesting that "atheos" is still based on the meaning of "theos" (just a lot earlier than I thought). The guy writing this is a theist and is strongly anti the view that atheism is not a active belief in the non-existence of deity but his arguments, whilst quite well written, seem to sum up atheist arguments and then just say "oh no they're not"

"The term atheos (a- means without; theos means god or gods) can be found in antiquity." Jon Meacham

Kyu

Yeah, I think when it comes down to it, I trust Wikipedia (with it's historian editors / language experts / peer reviewing) more than one theist who is completely biased. Wikipedia is a good resource in regards to popular articles.