Answer: BREAKTHESOUNDBARRIER

To "break the sound barrier" refers to the achievement of surpassing the speed of sound. The speed of sound, also known as Mach 1, is approximately 767 miles per hour (or 1,236 kilometers per hour) at sea level and at a temperature of 20 degrees Celsius. When an aircraft or any other object travels at or above this speed, it generates a cone-shaped shockwave called a sonic boom. Therefore, "breaking the sound barrier" means exceeding this speed and creating a sonic boom.

Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Hit Mach I … or a hint to answering eight pairs of consecutive entries in this puzzle. Explanations are generated by AI and may be inaccurate.