Related Clues:
- High-speed number
- Speed studier Ernst
- Barrier-breaking speed
- Flying-speed word
- Speed of sound number
- Number associated with a boom
- Sound barrier name
- Word often followed by a numeral
- Plane speed unit
- Ratio of fast flight
- Speed measure
- Supersonic unit
- Austrian physicist
- Big name in ballistics
- ___ 5 ('Speed Racer' car)