The term 'measure of speed' can be defined as a unit of measurement used to quantify the RATE of motion or speed of an object. The three crossword solutions for this term are KNOT, mach, and RATE. A KNOT is a unit of speed equal to one nautical mile per hour, which is approximately 1.15 miles per hour. Mach is a unit of speed equal to the speed of sound in air, which is approximately 767 miles per hour. Finally, RATE is a unit of speed equal to the number of units of distance traveled per unit of time, such as miles per hour or kilometers per hour.