'atheism' originates from Greek via New Latin and French, specifically the Greek word 'atheos' (ἀθεος), where the prefix 'a-' meant 'without' and 'theos' meant 'god'.

'atheism' changed from the Late Greek/Medieval Latin word 'atheismus' and Old French 'athéisme' and eventually became the modern English word 'atheism' through Middle English.

Initially, it meant 'without gods' or 'godless', but over time it evolved into its current meanings describing either the absence of belief in gods or the doctrine denying gods' existence.