# acceleration
## English
### Alternative forms

* acc.
* a.

### Etymology

First attested in 1531. From French accélération or more likely directly from Latin accelerātiō (“a hastening, acceleration”). Equivalent to accelerate +‎ -ion.

### Pronunciation

* enPR: əksĕlərā'shən, IPA: /əkˌsɛl.əˈɹeɪ.ʃən/, /ækˌsɛl.əˈɹeɪ.ʃən/, /ɪkˌsɛl.əˈɹeɪ.ʃən/
* Audio (US):(file)
* Rhymes: -eɪʃən

### Noun

acceleration (countable and uncountable, plural accelerations)
* (uncountable) The act of accelerating, or the state of being accelerated; increase of motion or action; as opposed to retardation or deceleration.
    A falling body moves toward the earth with an acceleration of velocity.
** 2022 January 12, Nigel Harris, “Comment: Unhappy start to 2022”, in RAIL, number 948, page 3:On the East and West Coast Main Lines in the 1950s/60s, for example, we saw the extinction of intermediate stations in order to create the same sort of accelerations that IRP is now promising. Back then, the priority was faster main line services, with wayside/intermediate stations paying the ultimate price.
* (countable) The amount by which a speed or velocity increases (and so a scalar quantity or a vector quantity).
    The boosters produce an acceleration of 20 metres per second per second.
** 1859-1860, Isaac Taylor, Ultimate Civilisation:A period of social improvement, or of intellectual advancement, contains within itself a principle of acceleration […]
* (physics) The change of velocity with respect to time (can include deceleration or changing direction).
* The advancement of students at a rate that places them ahead of where they would be in the regular school curriculum.

#### Usage notes

Acceleration in SI units is measured in metres per second per second (m/s$^2$), or in imperial units in feet per second per second (ft/s$^2$).

#### Antonyms

* (antonym(s) of “act or state, amount”): deceleration, retardation

#### Derived terms

* accelerational
* acceleration clause
* accelerationism
* accelerationist
* acceleration lane
* acceleration of gravity
* acceleration principle
* angular acceleration
* antiacceleration
* autoacceleration
* cardioacceleration
* celeration
* centripetal acceleration
* deacceleration
* four-acceleration
* hardware acceleration
* microacceleration
* nonacceleration
* overacceleration
* Planck acceleration
* plasma acceleration
* plasma wakefield acceleration
* postacceleration
* proper acceleration
* quadriacceleration
* reacceleration
* underacceleration

#### Translations
### See also

* displacement
* velocity
* jerk

### References

* ↑ Elliott K. Dobbie, C. William Dunmore, Robert K. Barnhart, et al. (editors), Chambers Dictionary of Etymology (Chambers Harrap Publishers Ltd, 2004 [1998], →ISBN), page 6

## Danish
### Noun

acceleration c (singular definite accelerationen, plural indefinite accelerationer)
* acceleration

#### Declension
### Further reading

* “acceleration” in Den Danske Ordbog

## Interlingua
### Noun

acceleration (plural accelerationes)
* acceleration

## Swedish
### Etymology

accelerera +‎ -tion

### Noun

acceleration c
* acceleration (increase or increasing of speed, of something concrete or abstract)
* (physics) acceleration

#### Related terms

* accelerator
* accelerera

### References

* acceleration in Svensk ordbok (SO)
* acceleration in Svenska Akademiens ordbok (SAOB)