activate

American  

[ak-tuh-veyt] / ˈæk təˌveɪt /

verb (used with object)

• activates,
  present (3rd person singular)
• activated,
  past participle,  past
• activating
  present participle

1. to make active; cause to function or act.

   Synonyms:

   start, actuate

   Antonyms:

   check, halt, stop

2. Physics.

   1. to render more reactive; excite.

      to activate a molecule.

   2. to induce radioactivity.

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

4. Chemistry.

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

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

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

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verb (used without object)

• activates,
  present (3rd person singular)
• activated,
  past participle,  past
• activating
  present participle

1. to become active or functional.

activate British  

/ ˈæktɪˌveɪt /

verb

1. to make active or capable of action

2. physics to make radioactive

3. chem

   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

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

5. to purify (sewage) by aeration

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

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Other Word Forms

Derived Forms

• activation
  noun
• activator
  noun
• nonactivation
  noun
• overactivate
  verb (used with object)
• superactivate
  verb (used with object)
• unactivated
  adjective

Inflected Forms

Participles

• activating
  present
• activated
  past

Conjugated Forms

Present

• activate
  simple
• activates
  simple
• have activated
  perfect
• has activated
  perfect
• am activating
  progressive
• are activating
  progressive
• is activating
  progressive
• have been activating
  perfect progressive
• has been activating
  perfect progressive

Past

• activated
  simple
• had activated
  perfect
• was activating
  progressive
• were activating
  progressive
• had been activating
  perfect progressive

Future

• will activate
  simple
• will have activated
  perfect
• will be activating
  progressive
• will have been activating
  perfect progressive

Etymology

Origin of activate

First recorded in 1620–30; active + -ate ¹

Explanation

To activate something is to start it off, trigger it, or set it in motion. A villain in a late-night movie might say, “Activate the robot chickens!” And then you’re free to activate your remote and change the channel. To activate something is to make it active. It’s not just for bad guys — when you activate a credit or library card, you can start using it. When a coach activates a player on a sports team, the player enters the game. If someone activates a bomb, you should run. If the pancakes you’re cooking burst into flames, you’ll probably activate the smoke alarm. And you should run.

Example Sentences

See Examples For:

activate activates activated activating

They activate what Mr. Lieberman refers to as “primeval cravings,” stimulating the brain’s reward centers and contributing to addiction and overconsumption.

From The Wall Street Journal ● Aug. 26, 2026

“The time that it takes to fully activate a performing arts center the size of the Vision has to occur in phases,” Wafer said.

From Los Angeles Times ● Aug. 24, 2026

They will also be able to activate "quiet times" when the tool will be switched off for them.

From BBC ● Aug. 18, 2026

They aren’t living drab or depressing lives when the Guardians of the Universe activate them — they’re faring pretty well, all things considered.

From Salon ● Aug. 16, 2026

“Malcolm, take the Athena cabin, activate plan twenty-three along the way, just like I showed you. Hold that position.”

From "The Last Olympian" by Rick Riordan

The catalyst first activates oxygen, producing highly reactive species.

From Science Daily ● Aug. 25, 2026

Keytruda is administered at the same time to help make sure the patient’s immune response activates against the leftover cancer cells.

From MarketWatch ● Aug. 20, 2026

In rats, for example, excess histidine can be converted into histamine, which activates brain receptors involved in controlling food intake.

From Science Daily ● Aug. 19, 2026

McBride fears the law would interfere with the making of devices like the one that activates his lifelike hand.

From Los Angeles Times ● Jul. 19, 2026

At some point my shoes light up and the hover feature activates, so that I’m hanging upside down in midair.

From "Amari and the Night Brothers" by B.B. Alston

But Roberts indicated over the weekend that he wasn’t necessarily expecting Rushing to be ready to be activated Tuesday.

From Los Angeles Times ● Sep. 1, 2026

Watch the video to learn how Campari turned a 107-year-old aperitif into a 21st century icon—and activated fierce competition in the process.

From The Wall Street Journal ● Sep. 1, 2026

The European Union said it had activated its Copernicus satellite surveillance system to help recovery efforts and was ready to provide more help, while the World Health Organisation said it had dispatched emergency medical supplies.

From Barron's ● Aug. 27, 2026

Palace activated that option in 2024, meaning Mateta's current deal is due to expire at the end of the season.

From BBC ● Aug. 22, 2026

Artemis activated the tri-band radio, broadcasting on revolving frequencies.

From "Artemis Fowl" by Eoin Colfer

Mobilizers focus on activating previously uninvolved portions of the electorate and bringing them to the polls; persuaders on changing the minds of regular voters.

From The Wall Street Journal ● Sep. 1, 2026

That result led the researchers toward indigo light, which is capable of passing through the lens while still activating the biological pathway they were investigating.

From Science Daily ● Aug. 26, 2026

Wearers can record video or take a photo by touching the frame - usually activating a light on the glasses in the process.

From BBC ● Jul. 24, 2026

Before activating my own Lightning Lane, I studied tutorials on Reddit and YouTube, where I learned that only suckers make a ride reservation and patiently wait for their designated time.

From The Wall Street Journal ● Jul. 20, 2026

The first Stormbreakers would have already begun leaving the plant, and in less than twenty-four hours the prime minister would be activating them.

From "Stormbreaker" by Anthony Horowitz

Related Words

• call up
• mobilize
• stimulate
• switch on
• trigger
• turn on