n. Any mass transit vehicle with an atheist ad or slogan on it, stemming from the original London bus ad with the words: “There’s probably no God. Now stop worrying and enjoy your life.” proposed by comedy writer Ariane Sherine and launched on Tuesday October 21 2008.

also n. An ad campaign to put atheist slogans on mass transit vehicles.

sometimes, n. A metaphorical construct suggesting that being a passenger implies atheism.
I got a picture of everyone on an atheist bus flipping off a Hummer! FUH2 fame, here I come!

Did you hear that New York is going atheist bus?

Since Friedrich married a Christian a few years ago he has really fallen off the atheist bus.
by plausitron March 29, 2010
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