deceleration
n. C / U B2 Upper Intermediate US //dɪˌsɛɫɝˈeɪʃən// UK //dɪsˌɛləɹˈeɪʃən// de·cel·er·a·tion
n. the process of slowing down. It is the opposite of acceleration and describes how quickly something loses speed.
n. the rate at which an object slows down; the negative of acceleration. Often used in physics and engineering to describe the reduction of velocity over time.
The car's sudden deceleration caused the passengers to lurch forward.
Engineers must calculate the rate of deceleration to ensure the train can stop safely within the station limits.
While the initial acceleration of the rocket was impressive, the final phase of the mission required a controlled deceleration to enter the correct orbital path around the moon.
From de- + (ac)celeration.