ultrasonic
The rocket came down at twice the speed of sound.
Though some of the planes can fly as fast as twice the speed of sound, they have to obey airspeed restrictions.
Supersonic defines a speed that is over the speed of sound, Mach 1.
SMART Vocabulary: related words and phrases Speed of motion
at full/half throttleidiom
briskness
burst of speed
celerity
clip
clock
ground speed
haste
hypersonic
hypervelocity
instantaneous velocity
light speed
momentum
pace
speed of light
speediness
supersonically
swiftness
throttle
velocity
You can also find related words, phrases, and synonyms in the topics:
Physics: particular theories & concepts