Michael Martin said this quote

“ If you look up 'atheism' in the dictionary, you will probably find it defined as the belief that there is no God. Certainly many people understand atheism in this way. Yet many atheists do not, and this is not what the term means if one considers it from the point of view of its Greek roots. In Greek 'a' means 'without' or 'not' and 'theos' means 'god.' From this standpoint an atheist would simply be someone without a belief in God, not necessarily someone who believes that God does not exist. According to its Greek roots, then, atheism is a negative view, characterized by the absence of belief in God. ”