To save this word, you'll need to log in.
Definition of acceleration
1a : the act or process of moving faster or happening more quickly : the act or process of accelerating rapid acceleration the acceleration of economic growth
b : ability to accelerate a car with good acceleration
2 physics : the rate of change of velocity with respect to time broadly : change of velocity
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
Semantic Drift Quiz
- Which of the following was once a synonym for fun?

Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Semantic Drift Quiz
A challenging quiz of changing words.
Take the quizA Thanksgiving Word Quiz
We are thankful for obscure words.
Take the quizSpell It
Can you spell these 10 commonly misspelled words?
Take the quizDictionary Devil
The dictionary has been scrambled—can you put it back together?
Play the game
Share acceleration
Time Traveler for acceleration
The first known use of acceleration was in the 15th century
See more words from the same century