Not surprisingly, this story's title brings to mind the dictionary definition of, well, a lottery: a happening determined by chance.
There's nothing in that definition about good or bad chance—but we're guessing your mind went straight to giant dollar signs and all-expenses-paid resort vacations.
In common usage, winning a lottery is cause for celebration. What becomes apparent by the end of Jackson's story, however, is that this lottery sure isn't one you'd want to win. By titling her story "The Lottery," Jackson keeps the real meaning of the story under wraps until the last possible second, allowing her message to deliver maximum impact.