acceleration

The word “acceleration” means an increase in speed, or the rate at which speed increases. In plain terms, the act or rate of speeding up — used for vehicles, physics, or general trends.

“Acceleration” is pronounced uhk-sehl-uh-RAY-shuhn (/əkˌsɛl.əˈɹeɪ.ʃən/ in IPA).

Here is “acceleration” used in a sentence: “The sports car is known for its fast acceleration.”

The opposite of “acceleration” — its antonyms — are deceleration and retardation.

“Acceleration” is a noun.

The word “acceleration” comes from Latin. From Latin acceleratio, "a hastening," from accelerare, "to accelerate.".

“Acceleration” is a fairly common word in modern English.

“Acceleration” has 2 distinct senses listed in this dictionary. The most common is: an increase in speed, or the rate at which speed increases.

Speed describes how fast something is moving at a given moment, while acceleration describes the rate at which that speed is increasing (or decreasing). An object can move at high speed with zero acceleration if its speed stays constant.

Acceleration refers to an increase in speed, while deceleration refers to a decrease in speed; both describe a rate of change in velocity, just in opposite directions. In everyday usage, "acceleration" is sometimes used loosely to cover both increases and decreases in speed.

Outside physics, "acceleration" commonly describes a speeding up of a process, trend, or timeline, such as the acceleration of a project or of a broader trend. This figurative sense keeps the core idea of something increasing in rate rather than literal speed.