| Answer | Crossword Clue |
|---|---|
| MACH | Speed-ratio number |
| MACH | -- number (speed ratio) |
| MACH | ... number (speed ratio) |
| MACH | Sound-speed ratio number |
| MACH | Number representing speed-sound ratio. |
| 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 |
| 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 |
