hypersonic

• POS: Adjective
• HYPHEN: hy=per=son=ic

CIDE DICTIONARY

hypersonic, n. [Pref. hyper- + sonic.].

 Pertaining to or moving at a speed greatly in excess of the speed of sound, usually meaning greater than mach 5. All speeds in excess of the speed of sound are supersonic, but to be hypersonic requires even higher speed.  [PJC]

OXFORD DICTIONARY

hypersonic, adj.
1 relating to speeds of more than five times the speed of sound (Mach 5).
2 relating to sound-frequencies above about a thousand million hertz.

Derivative

hypersonically adv.

Etymology

HYPER-, after SUPERSONIC, ULTRASONIC