The other definitions do not apply.
Thus their irrelevancy.
Unless you care to argue how they do apply to a baby being an atheist?
Well, if the definition of atheism is: "Someone who doesn't believe that gods exist" then obviously, this applies to the question of whether a baby is an atheist or not.
There is also another subtle variation: Basically, that even with the "lack of belief" definition, the assumption is that this only applies to people who can conceivable have opinions on these matters, and thus, cannot be applied to babies. This seems to me a reasonable position.
Yet you have not presented a single one...
You didn't ask, preferring to assume that not accepting the "lack of belief" definition simply indicated that the person was ignoring an inconvenient definition. I was merely pointing out that that assumption is ungenerous and inaccurate.
I am dismissing definitions that do not apply and applying the one that does.
Unlike some others who are defending their "position" by ignoring the definition that applies.
Thus the reason I flat out stated the definition that applies when I brought it up.
If you note, that's what my original post on this topic said: Babies are atheists... "If that's how you are defining atheism".
You took objection to this comment, by claiming that you could make such an absolute statement since you didn't ignore inconvenient definitions.
I still fail to see how you are not doing precisely that: Ignoring inconvenient definitions.
It's not a matter of applying the correct definition. It's a question of whether the definition you applied should even be considered a valid one.