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

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

Alexis Yim, a marketing professor at Radford University who co-authored a study on how cuteness impacts relationships with AI agents, said that “cute, appealing appearances” can activate the reward-related areas of the brain.

From MarketWatch ● Oct. 3, 2026

These videos, in particular, activate the reward circuitry of the brain with their novel, engaging and effortless nature, leading to instant and constant gratification.

From The Wall Street Journal ● Oct. 3, 2026

Our job, like those of so many arts workers across the country, was to activate creative magic in service of social cohesion and well-being.

From Los Angeles Times ● Oct. 3, 2026

Other studies have examined the disappearance of neurons that send the signals needed to activate muscles.

From Science Daily ● Sep. 24, 2026

To activate widget A, you insert doohickey B into slot C. Or you can delete the you, since it’s understood to be the subject.

From "Woe Is I" by Patricia T. O'Conner

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

In a research first, the scientists discovered that urolithin A activates a protein called PKGlα, which plays an important role in both blood vessel function and heart muscle relaxation.

From Science Daily ● Sep. 28, 2026

It activates dopamine, the neurotransmitter in the brain that triggers a feeling of relaxation.

From Los Angeles Times ● Sep. 27, 2026

"Moving the jaw muscles activates the big salivary glands. It cleans the mouth, it protects the teeth and it's vital for digestion."

From BBC ● Sep. 12, 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

Once activated, the switches produce electrical pulses lasting only a few picoseconds.

From Science Daily ● Oct. 2, 2026

Parents who already set up and activated accounts are not affected by the new rules, said Amber Salotto, managing director with RSM’s Washington National Tax compensation and benefits practice.

From MarketWatch ● Oct. 1, 2026

During the day, I probably took a nap so my brain is activated around 11 p.m. to midnight.

From Los Angeles Times ● Sep. 25, 2026

The Police Service of Northern Ireland says it has activated "mutual aid arrangements to support contingency planning for a policing operation" in Portadown on Sunday.

From BBC ● Sep. 24, 2026

My work computer was built into the chair’s circular base, and it activated itself automatically when I sat down.

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

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 resulting outcry shamed the network and demonstrated the activating power of public outrage.

From Salon ● Sep. 10, 2026

Many experimental compounds designed to stimulate PPARδ work by binding directly to the receptor and activating it.

From Science Daily ● Sep. 5, 2026

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

He flashed a smile, activating the zygomatic major.

From "Blink" by Malcolm Gladwell

Related Words

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