| 1. | a washing out of earth, gravel, etc., by water, as from an embankment or a roadway by heavy rain or by a flash flood. |
| 2. | the hole, break, or erosion produced by such a washing out. |
| 3. | Also, wash-out. Aeronautics. a warp in an airfoil that gives a decrease in the angle of attack toward the tip. Compare washin. |
| 4. | rainout. |
| 5. | Informal. an utter failure. |
| 6. | Informal. a person who has failed a course of training or study: air force washouts. |

| 1. | a contest, performance, or the like, that has been rained out. |
| 2. | Also called washout. the removal of radioactive particles or other foreign substances from the atmosphere by precipitation. |