According to the Oxford English Dictionary it did & still does?
quote:
The term atheism originated from the Greek ἄθεος (atheos), meaning "without gods", which was applied with a negative connotation to those thought to reject the gods worshiped by the larger society.
It was never meant non-belief in Gods but rather a rejection of particular concept of God.
Even Chrisitans were accused of Atheism because they denied the God of their Ancestors.
It was only in the 18th Century that people came to regard themselves as "atheists" which is non belief in Gods.