1. an act or instance of failing or proving unsuccessful; lack of success.
2. nonperformance of something due, required, or expected: a failure to do what one has promised.
3. a subnormal quantity or quality; an insufficiency: the failure of crops.
4. deterioration or decay, esp. of vigor, strength, etc.: The failure of her health made retirement necessary.
5. a condition of being bankrupt by reason of insolvency.
6. a becoming insolvent or bankrupt.
7. a person or thing that proves unsuccessful.