@Armor of God
“The two terms are related, in that they both refer to one’s view concerning God’s existence.”
They are related in their common usage, it is true. However, even your dictionary hints at their meanings in wider applications.
As
A has already pointed out, Atheist merely means without belief in a god, due to the “A” in front of “theist”, which negates the “theist” part of the word.
You’ll notice that Agnostic also has an “A” in front of it, this time negating “Gnostic”, which is derived from some old word(s) regarding knowledge.
Here’s what this means for all of us today:
Agnostic Atheist: “I have no knowledge of a God, and I don’t believe in a God”
Gnostic Atheist: “I know there is no God”
Agnostic Theist: “I have no knowledge of a God, but I believe in a God anyway”
Gnostic Theist: “I know there is a God”
So, just recapping “atheism” and “theism” are 2 different ranges on a scale of belief, “agnosticism” and “gnosticism” are two different ranges on a scale of knowledge.
I am an Agnostic Atheist, no joke, and no apology needed

I happily concede that common usage is veering away from the origins of the words.
“May I ask … what was the point? Are you trying to elicit a specific response from me?”
It was a two-pronged point. The first prong was to see if your current level of interactive communication with God was enough evidence for you to do something that is against your (otherwise) better judgement.
The second prong was to highlight the point that it makes me feel uneasy that many theists claim to get their ultimate benchmark of right and wrong and overall purpose in life from what is (potentially) a brutal dictator at worst, an uncomprehensible, unknowable entity at middle and a ficticious being at best.
I give these three options because as far as a “brutal dictator” is concerned, I disagree with the overall actions depicted in the bible and I don’t think there has yet been a satisfactory answer to the problem of evil. As far as an “uncomprehensible, unknowable entity” is concerned, a God of Deism is irrelevant to us. And I am currently unable to discern a difference between a God and a ficticious character. I don’t mean for these three options to spawn this thread going off on another tangent, just as explanation for the point I was making.
“Well, I must say that I am a little disappointed, and I hope you do have something to suggest to me in a little while. I currently have a few on my list, but work doesn’t allow me much time for “recreational” or “developmental” reading, other than that which is work-related!”
Now you’ve made me feel guilty! I have added your suggestion to my wishlist so I can keep an eye out for bargains on the amazon marketplace. 688 pages, nice! For you, I guess I will suggest “Shadows of Forgotten Ancestors” by Carl Sagan. I originally read it purely for enjoyment, but over the course of these three threads, it has been the work I have referenced most often. It has nothing to do with atheism at all, you understand, but it has been indispensable as a source of examples to give to people who think humans are somehow so far removed from animals.