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

February inflation cooled but remained elevated as total Consumer Price Index inflation decelerated to 2.8% from 3% and core CPI inflation decelerated to 3.1% from 3.3%. —Jason Schenker, Forbes, 12 Mar. 2025

About 11 minutes prior to touchdown, the spacecraft will ignite its engines again to decelerate from about 3,800 mph of lateral velocity to less than 100 mph (1.7 km/second to 40 m/second). —Kristin Shaw, Ars Technica, 27 Feb. 2025

With Mercury decelerating in speed during its retrograde, the cosmos is urging you to stop and smell the roses. —Lisa Stardust, Vogue, 26 Feb. 2025

To be sure, while still expected to be robust, Wedbush sees Amazon advertising services growth rate decelerating to 17.3% in 2025, which is a bit lower than the FactSet consensus estimate for 18% full-year growth. —Paulina Likos, CNBC, 20 Feb. 2025

Word History

Etymology

de- + accelerate

First Known Use

1899, in the meaning defined at transitive sense 1

Rhymes for decelerate

• abbreviate
• accelerate
• accommodate
• accumulate
• acuminate
• adjudicate
• adulterate
• affiliate
• agglomerate
• agglutinate
• alleviate
• amalgamate

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