| Term | Definition | Contributor | Modified |
|---|---|---|---|
| Maidu Indians--Religion and mythology | No definition provided | Christopher Rauch | 2023.12.01 |
| Maikainite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Mail-cars | No definition provided | Christopher Rauch | 2023.12.01 |
| Mail-chutes | No definition provided | Christopher Rauch | 2023.12.01 |
| Mailing guides | No definition provided | Christopher Rauch | 2023.12.01 |
| Mail order business | No definition provided | Christopher Rauch | 2023.12.01 |
| Mail-order business | No definition provided | Christopher Rauch | 2023.12.01 |
| Mail service | No definition provided | Christopher Rauch | 2023.12.01 |
| Mail steamers | No definition provided | Christopher Rauch | 2023.12.01 |
| Mail steamers--U.S.. | No definition provided | Christopher Rauch | 2023.12.01 |
| main | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Main | The region of the magnetosphere where themagnetic field lines are closed, but does not include the gaseous regiongravitationally bound to the body. | Ryan McGranaghan | 2023.04.16 |
| Main | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Maina Indians | No definition provided | Christopher Rauch | 2023.12.01 |
| Main belt asteroids | Asteroids in our solar system that are found in the area between Mars and Jupiter. | Ryan McGranaghan | 2023.04.16 |
| Main-belt comets | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Maine (Battleship) | No definition provided | Christopher Rauch | 2023.12.01 |
| Main sequence | An evolutionary stage in the life of a star when it generates its energy by the conversion of hydrogen to helium via nuclear fusion in its core. Stars spend 90% of their life on the main sequence. On the Hertzsprung-Russell diagram it appears as a track running from top left (high temperature, high luminosity, high mass) to lower right (low temperature, low luminosity, low mass). | Ryan McGranaghan | 2023.04.16 |
| Main sequence stars | No definition provided | Ryan McGranaghan | 2023.04.16 |
| maintenance | No definition provided | Ryan McGranaghan | 2023.04.16 |