activate

American  

[ak-tuh-veyt] / ˈæk təˌveɪt /

verb (used with object)

activated, activating

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)

activated, activating

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

• activation noun
• activator noun
• nonactivation noun
• overactivate verb (used with object)
• superactivate verb (used with object)
• unactivated adjective

Etymology

Origin of activate

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

Example Sentences

Nonetheless, the organization’s 80 acres are home to a variety of artist residencies, which use the windswept isolation of the desert to activate dormant ideas.

From Los Angeles Times • Mar. 31, 2026

The Pair Devices page is used to activate your Avast SecureLine VPN on your other devices.

From Salon • Mar. 21, 2026

"This opens doors to future therapies that may activate microglia without requiring antibodies. Understanding the importance of the Fc fragment helps guide the design of next-generation Alzheimer's drugs," concludes Prof. Bart De Strooper.

From Science Daily • Mar. 17, 2026

"What's truly scary about agents like OpenClaw is this: once they have your digital keys, they can theoretically access all the services you've authorised, and can autonomously decide when to activate them," Gao warned.

From Barron's • Mar. 13, 2026

These genes, in turn, activate “mapmaker” genes that make segments and split the body into its broad domains.

From "The Gene" by Siddhartha Mukherjee

Related Words

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