This short note will look at the history of Greek atheos and words ultimately derived from it (or in some cases modelled on it) in Greek, Latin, English, and a selection of other modern vernacular languages of western Europe. It will concentrate primarily on when each of these words first appeared in each language, with a brief consideration of its meaning. As writers far more expert on the history of atheism show in many places in this volume, investigating the history of atheistic beliefs throughout most of history is plagued by the difficulty that dire (and generally fatal) penalties could be incurred for the avowal of such beliefs. Most of the evidence for words meaning ‘atheism’, ‘atheist’, or ‘atheistic’ comes in the form of accusations levelled against individuals and/or their ideas or beliefs, and in some cases rebuttals of these, in which semantic clarity is often deliberately avoided.