It is a nonsensical definition.
Why? Show me why you think its illogical.
From the same online source:
"3. the non-existence or lack of."
In my definition, the lack of God (absence) in the observable cosmos is the only thing we can confidently say about it. It doesn't say anything definitive about his existence or non-existence.
From another source: (Merriam-Webster)
a state or condition in which something expected, wanted, or looked for is not present or does not exist : a state or condition in which something is absent
: a failure to be present at a usual or expected place
No god that has ever been proposed in the history of humanity is supported by any evidence.
Cofty and Wizztick, that may be true for the type of "omnipotent, omniscient, omnipresent" deity that you so fondly oppose to, but fact is, I have shown you a different type of deity, complete with a priesthood, temple and followers, and its existence is entirely verifiable by evidence. And you dismiss it just because it doesn't fit on your own definition of 'deity'?
Eden