Answer: machs

AnswerCrossword Clue
MACHSUnits of supersonic speed.
MACHSJet speed units
MACHSNumbers named for an Austrian physicist
MACHSVelocity units
MACHSMeasurements for SSTs
machsnumber indicating the ratio of the speed of an object to the speed of sound in the medium through which the object is moving
machsMACH, a number relating the speed of a body to the speed of sound