activate

American  

[ak-tuh-vayt] / 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

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Etymology

Origin of activate

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

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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

In one pathway, DNA and RNA originating from mitochondria activate immune responses that contribute to inflammation.

From Science Daily ● Oct. 27, 2026

“I think it’s safe to assume more families will activate their accounts because of SSA’s outreach,” one expert says.

From MarketWatch ● Oct. 22, 2026

“Every time you’re asking parents, especially low-income parents, to get through more hoops, they won’t get there. They still need to activate the account and it’s a separate process to claim the $1,000,” Boshara said.

From MarketWatch ● Oct. 21, 2026

Shely Aronov, chief executive of California startup InnerPlant, explains that when plants are attacked they start to activate genes to protect themselves.

From The Wall Street Journal ● Oct. 19, 2026

I heard a vacuum activate, sucking the indent’s regurgitated Oreos down the tube and into the floor.

From "Ready Player One: A Novel" by Ernest Cline

Some radiators have a snowflake symbol on the valve that activates the frost protection setting, meaning that if the room gets very cold, the radiator warms slightly to stop the pipes from bursting.

From BBC ● Oct. 23, 2026

That is the level of dedication to this project, which becomes obvious once the ensemble activates their full powers.

From Salon ● Oct. 7, 2026

Although the model features 501 billion parameters, it only activates 23 billion parameters per query, giving users the advantage of a large, powerful model without the high computing costs.

From MarketWatch ● Oct. 5, 2026

She writes that nicotine activates the body’s fight-or-flight response, increases heart rate and blood pressure and can disrupt sleep.

From The Wall Street Journal ● Oct. 2, 2026

The move activates his armguards—an enormous, glowing blue shield bursts outward from them in a circle, arcing protectively in front of us both.

From "Warcross" by Marie Lu

He said they activated flashing signs close by the bridge when vehicles of a certain height drove past.

From BBC ● Oct. 29, 2026

It has never been used, and investors remain uncertain over the conditions under which it could be activated.

From The Wall Street Journal ● Oct. 29, 2026

Newport Beach has declared a local emergency ahead of the tides and activated its emergency operations center, gearing up for flood prevention and response efforts.

From Los Angeles Times ● Oct. 24, 2026

Each fin could be activated independently using light, giving the researchers a simple way to control the robot's movements.

From Science Daily ● Oct. 23, 2026

“We’ll see about that,” I said as I grabbed her hand and activated my cuffs.

From "Glitch" by Laura Martin

It also will alert them to look for a communication from the Treasury Department with information about activating the account and receiving the $1,000 contribution, if the child is eligible.

From MarketWatch ● Oct. 21, 2026

For younger motorists, the first move when getting behind the wheel is to override the in-car infotainment system, including the radio, by activating Apple CarPlay or Android Auto.

From Slate ● Oct. 20, 2026

The primary and most convenient way to interact with the display, however, is by activating Siri AI with your voice.

From The Wall Street Journal ● Oct. 13, 2026

Orange County officials announced that they were activating their emergency operations center, which is required when two cities in the county proclaim a local emergency.

From Los Angeles Times ● Sep. 21, 2026

The sublimity of self-sacrifice activating the Cheerleaders overwhelmed him.

From "Travels with Charley in Search of America" by John Steinbeck

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