The ~ of a process or change is the fact that it is getting faster and faster.
He has also called for an ~ of political reforms.
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Acceleration is the rate at which a car or other vehicle can increase its speed, often seen in terms of the time that it takes to reach a particular speed.
Acceleration to 60 mph takes a mere 5.7 seconds.
Acceleration is the rate at which the speed of an object increases. (TECHNICAL)