| Answer | Crossword Clue |
|---|---|
| MACH | ... number indicating subsonic or supersonic speed. |
| MACHONE | Number indicating supersonic speed. |
| mach | number indicating the ratio of the speed of an object to the speed of sound in the medium through which the object is moving |
| machs | number indicating the ratio of the speed of an object to the speed of sound in the medium through which the object is moving |
