Failure noun 1. an act or instance of failing or proving unsuccessful; lack of success: His effort ended in failure. The campaign was a failure. 2. nonperformance of something due, required, or expected: a failure to do what one has promised; a failure to appear. 3. a subnormal quantity or quality; an insufficiency: the failure of reaching your goal time. 4. deterioration or decay, especially of vigor, strength, etc.: The failure of his health made retirement from the race necessary. 7. a…