[ ak-tuh-veyt ]
See synonyms for: activateactivatedactivatingactivation on

verb (used with object),ac·ti·vat·ed, ac·ti·vat·ing.
  1. to make active; cause to function or act.

  2. Physics.

    • to render more reactive; excite: to activate a molecule.

    • to induce radioactivity.

  1. to aerate (sewage) in order to accelerate decomposition of impure organic matter by microorganisms.

  2. Chemistry.

    • to make (carbon, a catalyst, molecules, etc.) more active.

    • to hasten (reactions) by various means, as heating.

  3. to place (a military unit or station) on an active status in an assigned capacity.

verb (used without object),ac·ti·vat·ed, ac·ti·vat·ing.
  1. to become active or functional.

Origin of activate

First recorded in 1620–30; active + -ate1

Other words for activate

Opposites for activate

Other words from activate

  • ac·ti·va·tion [ak-tuh-vey-shuhn], /ˌæk təˈveɪ ʃən/, noun
  • non·ac·ti·va·tion, noun
  • o·ver·ac·ti·vate, verb (used with object), o·ver·ac·ti·vat·ed, o·ver·ac·ti·vat·ing.
  • su·per·ac·ti·vate, verb (used with object), su·per·ac·ti·vat·ed, su·per·ac·ti·vat·ing.
  • un·ac·ti·vat·ed, adjective

Words that may be confused with activate Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use activate in a sentence

British Dictionary definitions for activate


/ (ˈæktɪˌveɪt) /

  1. to make active or capable of action

  2. physics to make radioactive

  1. chem

    • to increase the rate of (a reaction)

    • to treat (a substance, such as carbon or alumina) so as to increase powers of adsorption

  2. physiol to prepare by arousal (the body or one of its organs (e.g. the brain)) for action

  3. to purify (sewage) by aeration

  4. US military to create, mobilize, or organize (a unit)

Derived forms of activate

  • activation, noun
  • activator, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012