ad-

to, toward; addition; sometimes emphasis

Forms

ad-
ac- — Used before c in Latin.
af- — Used before f in Latin.
ag- — Used before g in Latin.
al- — Used before l in Latin.
ap- — Used before p in Latin.
ar- — Used before r in Latin.
as- — Used before s in Latin.
at- — Used before t in Latin.

Origin

Reconstructed Proto-Indo-European *ad, ‘to; near.’

Note

Later Latin-based spellings sometimes restored consonants that had disappeared in French.

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noun

accelerator

ak-SEL-uh-ray-ter/əkˈseləreɪtər/

Something that increases the speed of motion or progress.

The driver presses the accelerator farther down, and the car gains speed.

A two-panel close-up demonstrates a car accelerator: the driver's right foot presses the narrow right-hand pedal farther down, while the speedometer needle moves from a low to a higher speed.

Etymology

acLatinto, toward; addition; sometimes emphasis

+celerLatinswift

+atorLatina person or thing that performs an action

Built on the idea of making something swift, an accelerator was a “hastener.” That role extends naturally to a device or mechanism that makes motion or activity faster.

In context

MATLAB3:24

we depress the accelerator pedal some non-zero amount the car would then accelerate to a constant speed

Everything You Need to Know About Control Theory

More examples

The driver takes her foot off the accelerator.
The program serves as an accelerator for young businesses.
Magnets guide particles around the circular accelerator.

Forms

accelerator · accelerators

acceleration noun — A change in velocity over time.

beam noun — A directed stream of particles or radiation.

Similar words

particle accelerator: Full technical name, explicitly identifying the particles being accelerated.
atom smasher: Informal term, often emphasizing high-energy collisions in physics experiments.