2 can play that game.
Also, notice how the 2nd definition you provided uses the operator
"or", in the same way the wiktionary definition uses a semi-colon.
Moral = With concern for morality
Amoral =
Without concern for morality
Sexual = With sex
ASexual =
Without sex
Gnostic = With Knowledge
Agnostic = Without Knowledge
Archy = Ruler
Anarchy = Without Ruler
Theism = Belief in one or more "Gods"
Atheism = Without belief in a "God"
Explain to me what the A/An does to terms when it is applied. Does it describe the presence or lack of something?
The "a" is from the alpha privitive in Greek. It negates the word it's attached to. This can mean a simple lack of something as in some of the examples you gave. But in the case of "atheism" the explanation you gave doesn't work, as the definitions I provided showed. If you were writing a paper, would you cite wiktionary, or the Oxford English Dictionary? If you think I cherry picked sources (like I'm pretty sure you did), feel free to survey as many authoritative sources as you want, particularly standard reference works in philosophy, and see if you still think that. The "or" in the OED doesn't matter since disbelief doesn't mean "lack of belief" it means a positive rejection of belief.
One problem with the line of argument you gave is that it insists that the prefix "a-" in atheism has to modify the whole word with the suffix "-ism" already included. This suffix is one that we in modern English use to refer to a belief system (among other things), and that is it's function in the words "Judaism," "theism," "Pythagoreanism," "atheism," etc. The original Greek suffix -
ismos didn't have that meaning. Ancient Greek didn't have the abstract noun
atheismos, though it did have the adjective
atheos, meaning without a god, or denying the gods, and other cognates.
So if you take the root, "-the-," from the Greek
theos, meaning "god," and add to it the alpha privitive "a-," which negates things in English, as it did in Greek, and the suffix "-ism," which makes an abstract noun for a belief system in English, but not in ancient Greek, then if you combine the root and the suffix first "theism," and then negate it with the prefix, you get "not theism," which would be a lack of a belief in a god. That seems to be what you were trying to do. But if you combine the prefix and the root first "athe-," meaning "no god," and then add the suffix "-ism," to make an abstract noun for the belief system, you get what the word really means (or at least always meant until some atheists very recently started trying to cook up a new definition), which is a belief system based on the lack of a god.
Edit: Notice that the examples you gave didn't include any words with the suffix "-ism." But we could make such a word from one of your examples, "anarchism." Anarchism does not mean simply the mere lack of a belief in any given ruler. It means an ideology that positively asserts that there is or ought to be no ruler.