A "box office flop" refers to a film that fails to generate significant revenue compared to its production and marketing costs. When a movie is released, it is expected to attract audiences and earn money at theaters. If the earnings are much lower than anticipated, it is labeled a flop. Several factors can contribute to a box office flop, including poor marketing, negative reviews, or competition from other films. For example, a movie like John Carter faced criticism and struggled to recover its budget, ultimately being considered a box office failure.