Definition of hypersonic
1: of or relating to speed five or more times that of sound in air
https://www.merriam-webster.com/dictionary/hypersonic
Hypersonic weapons incorporate the speed of a ballistic missile with the maneuvering capabilities of a cruise missile. Hypersonic weapons refer to weapons that travel faster than Mach 5 (~3,800mph) and have the capability to maneuver during the entire flight. As a pentagon report stated, “While the designed speed of the hypersonic missile is faster than that of sound, its advantage lies in its enhanced maneuverability and smooth flight path, which is much harder to track than that of traditional missiles.”
https://missiledefenseadvocacy.org/missile-threat-and-proliferation/missile-basics/hypersonic-missiles/