| Answer | Crossword Clue |
|---|---|
| MACH | Speed of sound measure |
| MACH | Measure of speed relative to sound |
| RATE | Measure of speed |
| KNOT | Measure of speed |
| FPM | Measure of speed: Abbr. |
| RPM | Measure of speed: Abbr. |
| MACH | Eponym for a measure of speed |
| WARP | Measure of speed in "Star Trek" |
| MACHNUMBER | Measure of speed, in the jet age. |
| ERNST | Physicist Mach who lent his name to a measure of speed |
