Welcome to the forums! Hope you enjoy your stay and find it to be an informative place of discussion and hope you can show us a thing or two.
Though, obviously, with the amount of theists who come here, there are arguments we've heard a 1000 times and people may have their automatic responses to them.
It's pretty intense here, but if you're going to make claims, please prepared to be able to back them up, if you can't then what you say may be considered fictitious. Also, be aware that some sources may not be the most trust worthy, so we may even scrutinise your sources. As said, check over our rules and you ought to feel right at home.
However, good to see you're off to a head start and you're already using back up (via the use of the dictionary). I'm glad to see you're not here to convert, hopefully you will run it with an open mind and are willing to admit you're wrong when you are shown to be wrong and we'll offer you the same respect.
Oxford Dictionary defines it as 'a lack of belief
', just as you have a 'non-belief' in many things, including a great many things you've not even thought about. Atheists may have their beliefs, but their atheism at their core is a non-belief, an absence of belief, absence of an opinion. The atheist may
believe that gods do not exist, but that's additional to atheism.
Generally I use the Oxford Dictionary for my definitions over dictionary.com, sometimes I find their definitions aren't as accurate as Oxford's. Dictionary.com fails to mention 'non-belief', which is actually different to 'disbelief'.