decelerate

verb

de·​cel·​er·​ate (ˌ)dē-ˈse-lə-ˌrāt 

decelerated; decelerating

transitive verb

1

: to reduce the speed of : slow down

decelerate a car

2

: to decrease the rate of progress of

decelerate growth

decelerate soil erosion

intransitive verb

: to move at decreasing speed

deceleration

(ˌ)dē-ˌse-lə-ˈrā-shən 

noun

decelerator

(ˌ)dē-ˈse-lə-rā-tər 

noun

Synonyms

• brake
• retard
• slacken
• slow

Examples of decelerate in a Sentence

she decelerated the car as we entered the school zone

Recent Examples on the Web

The rate of services inflation continued to decelerate. —Bill Stone, Forbes, 19 Jan. 2025

When letting off the accelerator, the vehicle will begin to decelerate. —Mark Maynard, The Mercury News, 13 Dec. 2024

Inflation has decelerated significantly from peak levels. —Simon Moore, Forbes, 13 Jan. 2025

Dell and Australian aviation consultant Trevor Jensen told Reuters the reason the plane did not decelerate after hitting the runway was unclear. —David Faris, Newsweek, 29 Dec. 2024

Word History

Etymology

de- + accelerate

First Known Use

1899, in the meaning defined at transitive sense 1

Kids Definition

decelerate

verb

de·​cel·​er·​ate (ˈ)dē-ˈsel-ə-ˌrāt 

decelerated; decelerating

: to move or cause to move at decreasing speed : slow down

deceleration

(ˌ)dē-ˌsel-ə-ˈrā-shən 

noun

decelerator

(ˈ)dē-ˈsel-ə-ˌrāt-ər 

noun

Medical Definition

decelerate

verb

de·​cel·​er·​ate (ˈ)dē-ˈsel-ə-ˌrāt 

decelerated; decelerating

transitive verb

: to reduce the speed of : slow down

intransitive verb

: to move at decreasing speed

deceleration

(ˌ)dē-ˌsel-ə-ˈrā-shən 

noun