No problem, It’s interesting how differently the terms are used within and outside of the atheist community. I think it’s also important to realize that most Atheists are going to have more certainty when it comes to a specific God not existing, compared to the general concept of a God. It’s much more likely that some kind of God exists than the specific one of a given religion exists. Like I would personally put the general idea of a God existing at maybe 50% (like a God who created the universe and let nature take its course), but the specific God of a given religion that listens to your prayers at near 0%.

Antitheist is one term, I think the more common one in the same area would be Gnostic Atheist, which given my definitions from before would claim knowledge that gods don’t exist.

As with anything there are always more sub categories, some go as far as to say knowledge of God is unknowable, or that no form of a God exists, but most seem to stick with Agnostic Atheist, or just Atheist.