The definition that I hear the most often is that atheism is a LACK of belief in gods, also sometimes characterized as agnostic atheism. This generally is the position taken in a discussion / debate where the existence of god is asserted. Such a positive assertion brings with it the burden of proof to substantiate it ... which usually doesn't work out so well for most believers. We simply deny their assertion, as a denial carries no burden with it.
The statement: "There are no gods" is held by many in the atheist community (including yours truly!), usually with the Null Hypothesis supporting it, but its problem is that it is exceptionally difficult to prove a negative. For myself, no, I don't think any gods exist, but I also understand the exigencies of making such a statement as a part of a conversation where that contention may come into question.
Meantime, GREETS, Darcy, and welcome to Atheist Nexus!
Loren, I like your response to Darcy.
Welcome to our group, Darcy. For me atheism is simply declining to believe in any deities. The only evidence needed to support this is the utter and complete lack of evidence or any reason whatsoever to believe in them. Religionists like to claim that "It takes more faith" to believe in the big bang or evolution than it does to believe in creationism, imho a completely fatuous argument. As Salman Rushdie recently reminded us, science proves things to us; it doesn't require us to believe anything.
Bertold, I like your response to Dary, too.
Darcy, I first call myself a humanist. But when pressed, I say when it comes to the disgusting god of Abraham and Isaac -- "Abe, you and Ike meet me at Sacrifice Rock. And bring the knife." -- I'm a total atheist. For such an unlikely combination of egoist and sadist to be in charge of everything doesn't fly. If you ask was there an intelligence behind the creation of the universe, I'm an agnostic. It seems most unlikely; there are better ways to explain it all; but I'm slightly less than 100% convinced there is no such. This may help you, or somebody, or it may just add confusion. But that's what works for me.
Jerry, your response to Darcy works for me too.
Welcome Darcy. You will find that many of us have different ways of putting things also about belief or non belief. I'm a former theist who studied for the ministry, and I do not have a LACK of belief in god or gods. I say this because many believers today try to convert me or "get me back on the right path." Save your time, please. What I LACK is the evidence of belief. In world history there has never been any evidence that would support gods or god belief. It's a fact. This is when believers tell you that you just have to have faith.
Let me explain "faith." This is when you think daily about your old car turning into a new Ferrari but deep down you know it is never going to happen. Even so, you try to believe it anyway.
Michael, yours is a good answer, too. I'm getting a feeling here that there exist many ways to express our experience or lack of experience of evident.
What I LACK is the evidence of belief.
Michael, on a scale of from cold to hot, you're warmer than the others so far.
OK, it is getting to be multiple answers to a profound question. I like your answer, too, James.
James, on that cold-to-hot scale, you are closing in on hot.
The adjective 'clearly' implies a need to convince.
Welcome, Daniel c Dennett in his book. Breaking the spell gives the best definition of belief and belief in belief which can be looked up on the internet. The late Richard Higgins discussed the definition of God often. May videos on you tube can be found where he discusses it.
To answer your question I would Invert the premise. There is no God so therefore he cannot be defined. It's that simple. The argument then becomes an abstract argument on what does not exist in the first place. The many answers you speak of are simply made up of imaginative speculation. I found it not to difficult to understand once I came to this conclusion.
Atheist have no universal creed as many theist do. They are often in differing states of growth and understanding. I personally believe there is no God. Others may not believe in God, that is the moral principles, or religious beliefs associated with God. This can but a very abstract subject dependent upon a given persons definition of belief.
Hope I was helpful. Best wishes and good luck!