- 1[uncountable, singular] acceleration (in something) an increase in how fast something happens an acceleration in the rate of economic growth
- 2[uncountable] the rate at which a vehicle increases speed a car with good acceleration acceleration from 0–60 mph in 11.2 seconds
- 3[uncountable] (physics) the rate at which the velocity (= speed in a particular direction) of an object changes acceleration caused by gravity
Check pronunciation: acceleration