First attested in the 1520s. Either from , perfect passive participle of accelerō ("I accelerate, hasten"), formed from ad + celerō ("I hasten"), which is from celer ("quick") (see celerity), or back-formation from acceleration.

• (RP) IPA: /ək.ˈsɛl.ə.ˌɹeɪt/, /æk.ˈsɛl.ə.ˌɹeɪt/, /ɪk.ˈsɛl.ə.ˌɹeɪt/

accelerate (accelerates, present participle accelerating; simple past and past participle accelerated)

1. (transitive) To cause to move faster; to quicken the motion of; to add to the speed of.
2. (transitive) To quicken the natural or ordinary progression or process of.

   to accelerate the growth of a plant, the increase of wealth, etc.

3. (transitive, physics) To cause a change of velocity.
4. (transitive) To hasten, as the occurrence of an event.

   to accelerate our departure

5. (transitive, education) To enable a student to finish a course of study in less than normal time.
6. (intransitive) To become faster; to begin to move more quickly.
7. (intransitive) Grow; increase.

• (to cause to move faster) hasten, quicken, speed up; see also Thesaurus:speed up
• (to quicken progress) expedite, further,
• (to hasten the occurrence of an event) advance, forward

• decelerate
• retard
• unaccelerate

• French: accélérer
• German: beschleunigen
• Italian: accelerare
• Portuguese: acelerar
• Russian: ускоря́ть
• Spanish: acelerar, embalar

• French: accélérer
• German: beschleunigen
• Italian: accelerare
• Portuguese: acelerar, apressar
• Russian: ускоря́ться
• Spanish: acelerar

• French: accélérer
• German: eilen, beeilen
• Italian: affrettare
• Portuguese: acelerar, apressar
• Russian: ускоря́ть
• Spanish: acelerar, apresurar

• French: accélérer
• German: schneller werden, beschleunigen
• Italian: accelerare
• Portuguese: acelerar
• Russian: ускоря́ться
• Spanish: acelerar, embalarse

accelerate (not comparable)

1. (archaic) Accelerated; quickened; hastened; hurried.
   • 1662, Thomas Salusbury, Galileo's Dialogue Concerning the Two Chief World Systems, Dialogue 2:

     ... a general knowledg of the definition of motion, and of the distinction of natural and violent, even and accelerate, and the like, sufficing.