Atheist: a person who does not believe in the existence of a god or any gods
This is consistent with atheist writers like Dawkins.
Can you explain the theological background of Chambers, since you seem to think he's some sort of authority on the matter?
Edit: This from wikipedia on the Chambers dictionary:
The Chambers Dictionary is widely used by British crossword solvers and setters, and by Scrabble players (though it is no longer the official Scrabble dictionary). It contains many more dialectal, archaic, unconventional and eccentric words than its rivals, and is noted for its occasional wryly humorous definitions. Examples of such definitions include those for éclair ("a cake, long in shape but short in duration") and middle-aged ("between youth and old age, variously reckoned to suit the reckoner").[2] These jocular definitions were removed by the publisher in the 1970s, but many of them were reinstated in 1983 because of the affection in which they were held by readers.
So you're using a dictionary whose purpose is entertainment, rather than accuracy.. and insisting this is the definition we should all use? What a joke.