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.

---

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)

---

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

China’s decision to activate its leverage changed all this.

From The Wall Street Journal ● Sep. 8, 2026

By making certain stress-related genes easier to activate, early adversity may leave the brain more reactive and less able to tolerate future stress.

From Science Daily ● Aug. 26, 2026

In a more positive development, Will Smith faced live pitching for the first time since June, and Roberts said that the plan is to activate the catcher during the first week of September.

From Los Angeles Times ● Aug. 22, 2026

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

From BBC ● Aug. 18, 2026

At bedtime they turn the lamps to near darkness and activate safety lights in each space.

From "Mockingjay" by Suzanne Collins

"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

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

But the illness brought on by the worms, and the stirring awareness of her mortality, activates what Ms. Day calls a “coup of the primordial.”

From The Wall Street Journal ● Jul. 29, 2026

Instead, the sprinkler system activates and floods the entire house, turning a contained problem into widespread damage.

From Science Daily ● Jul. 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

Authorities activated a mass-casualty response plan, with 130 firefighters, five medical teams and 80 vehicles drafted in.

From Barron's ● Sep. 12, 2026

The program focuses on understanding how these receptors change shape, become activated, and transmit signals inside cells.

From Science Daily ● Sep. 9, 2026

Somewhere inside me, a tiny rewards-program customer had been activated.

From Salon ● Sep. 6, 2026

The setup has afforded Rushing more regular at-bats than initially expected when the Dodgers activated him this week.

From Los Angeles Times ● Sep. 5, 2026

Electricity had overwhelmed her circuits, but then her recovery program activated, and after a moment, she was fully functional again.

From "The Wild Robot Protects" by Peter Brown

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

From Salon ● Sep. 10, 2026

Some resistant prostate tumors survive by activating alternative biological pathways that reshape the identity of their cells.

From Science Daily ● Sep. 8, 2026

In animal models, the therapy slowed the growth of pancreatic tumors by selectively activating T cells that fight cancer.

From Science Daily ● Aug. 19, 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

He flashed a smile, activating the zygomatic major.

From "Blink" by Malcolm Gladwell

Related Words

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