verb (used with object), ac·ti·vat·ed, ac·ti·vat·ing.

to make active; cause to function or act.
  1. to render more reactive; excite: to activate a molecule.
  2. to induce radioactivity.
to aerate (sewage) in order to accelerate decomposition of impure organic matter by microorganisms.
  1. to make (carbon, a catalyst, molecules, etc.) more active.
  2. to hasten (reactions) by various means, as heating.
to place (a military unit or station) on an active status in an assigned capacity.

Origin of activate

First recorded in 1620–30; active + -ate1
Related formsac·ti·va·tion, nounnon·ac·ti·va·tion, nouno·ver·ac·ti·vate, verb (used with object), o·ver·ac·ti·vat·ed, o·ver·ac·ti·vat··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
Can be confusedactivate actuate stimulate

Synonyms for activate

1. actuate, start, turn on, set going.

Antonyms for activate Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for activation

Contemporary Examples of activation

Historical Examples of activation

  • But non-military items also arrived for activation and test.

    The Machine That Saved The World

    William Fitzgerald Jenkins

  • The scientist set the controls and turned on the activation switch.

    The Golden Skull

    John Blaine

  • There is no known explanation for this type of activation of the enzyme.

    The Chemistry of Plant Life

    Roscoe Wilfred Thatcher

  • How this activation is being aided and accelerated by another source of dynamic energy: irradiation from the sun.

    The Brain

    Alexander Blade

  • It is usually measured by inserting materials of known composition and measuring their activation.

British Dictionary definitions for activation


verb (tr)

to make active or capable of action
physics to make radioactive
  1. to increase the rate of (a reaction)
  2. to treat (a substance, such as carbon or alumina) so as to increase powers of adsorption
physiol to prepare by arousal (the body or one of its organs (e.g. the brain)) for action
to purify (sewage) by aeration
US military to create, mobilize, or organize (a unit)
Derived Formsactivation, nounactivator, 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

Word Origin and History for activation

1906, noun of action from activate (v.).



1620s; see active + -ate (2). Related: Activated; activating.

Online Etymology Dictionary, © 2010 Douglas Harper