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 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

The researchers found that older adults are more likely to activate opposing muscles around the ankle at the same time.

From Science Daily ● Aug. 16, 2026

“We’re endeavoring to activate that park a lot more, working with our community members.”

From Los Angeles Times ● Aug. 13, 2026

When Barcelona decided not to activate the £26m clause to buy the 28-year-old, whose United contract expires in 2028, it was thought to be a negotiating tactic, aimed at taking Rashford on another loan.

From BBC ● Aug. 5, 2026

They activate and silence genes, thereby defining the embryo’s axis from head to tail.

From "The Gene" by Siddhartha Mukherjee

Previous research showed that EPS8 accumulates as worms grow older and activates damaging stress responses that shorten their lifespan.

From Science Daily ● Aug. 3, 2026

It activates if one spouse decides to stay at home and give up a career.

From The Wall Street Journal ● Jul. 15, 2026

They would simply make unmistakably clear that the executive cannot determine whether Congress’ statutory commands ever become operative by controlling the very event that activates them.

From Slate ● Jun. 26, 2026

The declaration activates the city’s emergency response structure, directs departments to assess damages and costs, and requests state assistance to support firefighting, cleanup, environmental monitoring and community recovery efforts.

From Los Angeles Times ● Jun. 20, 2026

“But this one activates a radio jammer so no one can use electronic devices to listen in on you.”

From "City Spies" by James Ponti

Most of the duties will go into effect next month, the White House said, though tariffs on drones and components that aren’t “particularly sensitive” will be activated in six months.

From MarketWatch ● Aug. 14, 2026

"We were able to identify numerous genes and signaling pathways that are temporarily activated during repair. They could serve as starting points in the future for influencing post-disease and -injury regeneration processes," Weber stresses.

From Science Daily ● Aug. 12, 2026

Because working-class voters, as they tell us themselves, are not simply waiting to be activated by the right program, messenger or phrase.

From Salon ● Aug. 9, 2026

“Having space available that could be activated during the Olympic Games could attract some of the countries whose teams are participating.”

From Los Angeles Times ● Aug. 5, 2026

For a moment Michael thought the EGG had activated and placed Ridge in some kind of frozen physical state between universes, but then Ridge exhaled and said, “There are several reasons it might not work.”

From "The First State of Being" by Erin Entrada Kelly

"What we're saying is that at least part of coffee's health benefits may come through binding and activating this receptor," Safe said.

From Science Daily ● Jul. 19, 2026

Immune checkpoint inhibitors work by activating the body's own T cells and encouraging them to move into tumors where they can destroy cancer cells.

From Science Daily ● Jun. 25, 2026

From an evolutionary perspective "stress is what keeps us alive" by activating our flight-or-fight response.

From BBC ● Jun. 22, 2026

More time is devoted to setting up the dramatic situation than to activating it.

From Los Angeles Times ● Jun. 19, 2026

He continued to expand the search, activating manhunters in Delaware and Pennsylvania.

From "Chasing Lincoln's Killer" by James L. Swanson

Related Words

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