| 1. | the extinguishing or concealment of all visible lights in a city, military post, etc., usually as a precaution against air raids. |
| 2. | a period during a massive power failure when the lack of electricity for illumination results in utter darkness except from emergency sources, as candles. |
| 3. | Theater.
|
| 4. | Pathology.
|
| 5. | a brief, passing lapse of memory: An actor may have an occasional blackout and forget a line or two. |
| 6. | complete stoppage of a communications medium, as by a strike, catastrophe, electrical storm, etc.: a newspaper blackout; a radio blackout. |
| 7. | a stoppage, suppression, or obliteration: a news blackout. |
| 8. | a period during which a special sales offer, fare rate, or other bargain is not available: The airline's discount on fares does not apply during the Christmas week blackout. |
| 9. | Radio and Television. a prohibition that is imposed on the broadcasting of an event and has the purpose of encouraging or ensuring ticket sales. |

blackout black·out (blāk'out')
n.
Temporary loss of consciousness due to decreased blood flow to the brain.
Temporary loss of memory.