hypersonicPronunciation: /hʌɪpəˈsɒnɪk/Definition of hypersonic adjective 1relating to speeds of more than five times the speed of sound (Mach 5). 2relating to sound frequencies above about a thousand million hertz. Derivatives hypersonically adverb Origin: 1930s (in sense 2): from hyper- 'beyond, exceeding', on the pattern of supersonic and ultrasonichypersonic in other Oxford dictionaries Definition of hypersonic in the US English dictionary
