ac·cel·er·a·tion 
/ɪkˌsɛləˈreɪʃən/ noun
/ɪkˌsɛləˈreɪʃən/ noun 1 : the act or process of moving faster or happening more quickly : the act or process of accelerating [noncount] ▪ The car delivers quick/rapid acceleration. ▪ The car has good acceleration. [=the car is able to accelerate quickly] ▪ There has been some acceleration in economic growth. [singular] ▪ There has been an acceleration in economic growth. 2 [noncount] physics : the rate at which the speed of a moving object changes over time
