Your argument that I am responsible for choosing a definition when your definition comes from some nameless person that you once read or heard, is bit rich. The definition at Dictionary.com is backed by Collins English Dictionary - Complete & Unabridged 10th Edition.
Where did I say that I was
not responsible for choosing the definition I use?
And why are lexographers authoritative on this subject?
I urge you not to give a flippant, dismissive answer to that second question.
Now, if you think you know better than a lexicographer, fine for you, but don’t expect others to agree or think your idea is better. If you can find a dictionary that has your definition, please go ahead.
See above. Definitions are subjective. There is no authority in their usage other than what humans grant. So, which humans do you want to control what defines you?
Your claim that dictionaries are subjective (and here you have to show that this dictionary is subjective and that the particular definition is subjective too) is less than helpful as it is apparent that you, like Humpty-Dumpty think a word can mean what ever you want it to mean. I suppose you have some feeling that your definition is not subjective 
If the definition is not shared, then I agree, communication can't yet take place using it. And why would you suppose something as mind-crogglingly stupid as what I just underlined in the above quote? Of course my definition is subjective. Are you trolling, sir?
I suggest you define atheist as a, “A neonate” that will solve all your logical problems.
Okay. Yeah, you're trolling.
It is clear that you are not reading what I write but what you think I am writing. Naturally, you have the advantage, expressed in your last post, that you know my mind.
I am looking for where I expressed this. So far, I have been going on what you've written. Looking over my last two posts, I cannot find any suggestion to the contrary. It is possible I have misread you, of course, but I have been trying to ensure that when I talk about your position on something, it's clear that I am talking about
my interpretation of your position.
Usually that sort of thing goes without saying, but you've turned it into some sort of tactical device for argumentation. Blegh.
Tell me, do you think there is any point at all in dictionaries?
Of course. They report on usage. They are useful for telling us how other people are using words, for reporting on usage. You are employing them in the opposite direction, for some reason: Usage based on the unshakeable authority of the dictionary.
You associate me with a ridiculous idea and it is not ad hominem?
You set up an argument about “not being surprised if I defined atheism as "worship of Satan"” and that is not strawman?
Now you are bald-faced lying about what I said. That is effectively trolling.
You explanations are as chaff before the wind. 
You need that dictionary.
I am coming to agree with the bolded text. I have come to doubt that any explanation I offer for anything would be treated fairly by you, no matter how it was worded or what its point was.
Well of course it is! Who else’s would it be? I have taken the view that what you write is your decision – am I right?
Uhh, yeah. This needed to be stated...?
Apart from an affinity for the definitions offered by Dictionary.com, what arguments do you have in favor of using that definition?
“Apart from that Mr Lincoln, how did you enjoy the concert…” Is that a serious question?
Well, mine was. Totally, dead-pan serious.
Look, I’m not here to defend Collins Dictionary; it is simply a good dictionary. Nor am I going to chose 10 other dictionaries only to have you say, “all dictionaries are subjective” (a generalisation that is not helpful.)
It would be off-topic to which term is better, anyway. Just as your citation of Collins is not relevant to that topic.
You don’t like it,? You can explain why Collins Dictionary is wrong,
Where have I indicated that they are wrong? Wrong about what, the definition? Calling a definition "right" or "wrong" is a category error.
and can you give the authority for your statement, I've seen some atheists define the word as (to paraphrase) "a reasoned rejection of all supernatural claims".
It's in one of Xphobe's old posts, from another thread on this topic. Do you want me to dig it up? He gave reasoning for it, too.
and why you think that the word “reasoned” is applicable to a neonate?
I never indicated that I thought this. I made it clear that it wasn't my definition. And you say
I need to read
your posts better?
Whist you’re at it, give me your definition of atheist – remember you can’t use dictionaries. I will check them against several reputable dictionaries and ask you to explain why your definition differs.
I've already given it. I would do so here, if I felt I was dealing with an honest interlocutor. But given all the trolling and inflamatory crap in your post so far, I'm not inclined to do your work for you.
As for why it differs from yours, I gave that reasoning in my last post to jaimehlers, who seems to be keeping a cooler head than I am, and a far cooler head than you are, based on all our posts.
In the meantime, can we progress with the Dictionary.com definition?
I see no reason to, given its flaws.