No. An atheist (no god or without god) is sure that they don't believe in gods. However not being sure has a name as well, it is most often called agnostic (not knowing) behavior.
From "not being sure" you may progress through studying the question and discussing the issue to being either an atheist, agnostic or theist. A fourth option, non-theist, best describes groups like Buddhists who don't feel the issue of whether there is a god or not is worthwhile pursuing.
You are Atheist
No, if you are an atheist, you don't believe in god.
No, he's an agnostic, meaning that he's not sure whether there's a God or not.
No. The definition of an Atheist is the position of rejection of ALL god claims. Therefore, an Atheist would have no god or gods
By definition, an atheist is a person who does not believe in God, and atheism is disbelief in God.
No, he's an agnostic, meaning that he's not sure whether there's a God or not.
Atheist - If he is sure there there is no specific god because of the impossibility and/or improbability of his existence. Agnostic - Not sure whether there is a god or not. Usually does not care. An atheist is the opposite of a theist. The theist believes there is evidence for the existence of their favorite god. The atheist does not. It would be illogical for the atheist to "deny" the existence of something for which there is no evidence. Atheism is merely the lack of a belief. Knowledge is absolute. Since nobody can know with absolute certainty no gods exist, everyone is agnostic. So the so-called "agnostic" has the same lack of knowledge as the atheist or theist has. It's just commonly accepted that an agnostic does not commit either way.
Is considered an atheist by the mainstream.
Atheist answerWell, just say that you are an atheist and that you don't believe in god.
Vladimir Lenin was an atheist, he did not believe in God.
That's pretty much the definition of "Atheist" so yes, an atheist is someone who doesn't believe in god or gods.
Such a person is called an ATHEIST.