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

When we look at relaxing paintings, we actually activate our pain analgesic response.

From Los Angeles Times • Apr. 8, 2026

By submitting to men, tradwife proponents argue, a woman will activate his chivalric urge to protect and provide.

From Salon • Apr. 8, 2026

The couple had travelled from Houston to the Louisiana base to obtain a military ID for Ramos and activate her military spouse benefits, with plans to move her onto the base over Easter weekend.

From BBC • Apr. 7, 2026

Treasury will reach out to families who have signed up when accounts are ready to activate in coming months.

From The Wall Street Journal • Apr. 6, 2026

He would make the final mixture at the last moment to activate it.

From "Strange the Dreamer" by Laini Taylor

Related Words

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