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

Unlike other retrons, these systems rely on DNA to activate a toxin rather than keep one suppressed.

From Science Daily ● Oct. 31, 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 instructed it to activate its cloaking device as soon as it dropped out of hyperspace, then locate me on the planet’s surface and land somewhere nearby.

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

So I sit in his seat and watch his computer screen as he activates a YouTube video.

From "The Running Dream" by Wendelin Van Draanen

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

"I don't know how long she was on the floor for before she activated the alarm," he said.

From BBC ● Oct. 24, 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

But the TPI, which has never been used, can be activated only in cases where a bond sell-off is considered unjustified.

From Barron's ● Oct. 21, 2026

And second, some genes are activated by external triggers or by random chance.

From "The Gene" by Siddhartha Mukherjee

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 Netherlands hopes to insulate the court by activating the European Union’s “blocking statute,” a rule that would ban EU companies from complying with the sanctions and thereby expose them to U.S. secondary sanctions.

From The Wall Street Journal ● Oct. 14, 2026

Instead of simply shutting down a cancer-promoting protein, the scientists designed a small molecule that connects it to another protein capable of activating the cell's built-in death program.

From Science Daily ● Oct. 8, 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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