acceleration
n. C / Un. an increase in speed or the rate at which something speeds up. You use this to talk about vehicles moving faster, or when a process starts happening more quickly.
n. the rate at which an object changes its velocity over time, or the act of increasing speed. Frequently applied in non-scientific contexts to describe processes that are developing increasingly quickly.
The new sports car has amazing acceleration.
The sudden acceleration of the train caught the standing passengers off guard, causing several to stumble.
Economists noted a sharp acceleration in inflation during the third quarter, driven primarily by supply chain disruptions and surging energy costs.
Etymology tree Proto-Indo-European *h₂éd Proto-Italic *ad Proto-Italic *ad- Latin ad- Proto-Indo-European *kel-der. Latin celer Proto-Indo-European *-h₂ Proto-Indo-European *-éh₂ Proto-Indo-European *-yéti Proto-Indo-European *-eh₂yéti Proto-Italic *-āō Latin -ō Latin celerō Latin accelerō Proto-Indo-European *-tisder. Proto-Italic *-tjō Latin -tiō Latin accelerātiōder. English acceleration First attested in 1531. From French accélération or more likely directly from Latin accelerātiō (“a hastening, acceleration”). Equivalent to accelerate + -ion.
Uncountable when referring to the general physical concept; countable when describing a specific instance or a measurable rate.