Select the most appropriate one-word substitution for the given words.

speed greater than that of sound

supersonic

The most appropriate one-word substitution for the given words "speed greater than that of sound" is supersonic.

• Harmonic means having a pleasing or harmonious sound.
• Cacophonic means having a harsh or unpleasant sound.
• Subsonic means having a speed less than that of sound.

Supersonic speed is a speed greater than the speed of sound. The speed of sound in air is approximately 767 miles per hour (1,235 kilometers per hour) at sea level. Objects that travel at supersonic speed create a sonic boom, which is a loud noise caused by the shockwaves that are generated when the object breaks the sound barrier.