activate

verb

ac·​ti·​vate ˈak-tə-ˌvāt 

activated; activating

transitive verb

: to make active or more active: such as

a(1)

: to make (something, such as a molecule) reactive or more reactive

(2)

: to convert (something, such as a provitamin) into a biologically active derivative

b

: to make (a substance) radioactive

c

: to treat (a substance, such as carbon or alumina) so as to improve adsorptive properties

d(1)

: to set up or formally institute (an organized group, such as a military unit) with the necessary personnel and equipment

(2)

: to put (an individual or unit) on active duty

intransitive verb

: to become active

activation

ˌak-tə-ˈvā-shən 

noun

activator

ˈak-tə-ˌvā-tər 

noun

Synonyms

• actuate
• crank (up)
• drive
• move
• run
• set off
• spark
• start
• touch off
• trigger
• turn on

Examples of activate in a Sentence

Touch the screen to activate the system.

activate and then deactivate a mechanism

The camera is activated by pushing a button.

The bomb was activated by remote control.

Sunlight activates a chemical reaction in the plant's leaves.

vitamins that activate the growth of new cells

The President has activated the reserves.

Recent Examples on the Web

Post brew, the machine automatically activates a keep-warm setting that maintains the coffee’s hot temperature for up to two hours. —Stephanie Osmanski, Southern Living, 13 Apr. 2024

The drone offers three difficulty levels: Level one helps kiddos learn flying basics, level two activates both joysticks but maintains the self-leveling feature, and level three gives users the freedom and tools to do flips and fly at faster speeds. —Maya Polton, Parents, 12 Apr. 2024

The threatening forecast led organizers of the Texas Eclipse Festival to end the celebration early Monday and Texas Gov. Greg Abbott to activate emergency response resources. —Gabe Hauari, USA TODAY, 10 Apr. 2024

Read: Demon mode activated Burkhart watched Arbaugh play hands-free computer chess with a mix of approval and frustration at how clearly the demo was created for investors and Musk fans, not for disabled people like him. —S. I. Rosenbaum, The Atlantic, 7 Apr. 2024

In many cases, this actually activates the body’s inflammatory response, and leaves it on, even when it should be turned off. —Kari Nadeau, STAT, 4 Apr. 2024

The agency’s State Emergency Operations Center has been activated in response to the storm. —Marlene Lenthang, NBC News, 4 Apr. 2024

Roberts said Buehler probably would need to reach 90 pitches — and make three more minor league starts — before the Dodgers consider activating him. —Bill Shaikin, Los Angeles Times, 1 Apr. 2024

Amazon’s Echo Shows have their own special tricks and ways to activate them. —Nena Farrell, WIRED, 29 Mar. 2024

Word History

Etymology

active entry 1 + -ate entry 4, probably as adaptation of French activer, going back to Middle French, derivative of actif active entry 1

First Known Use

1624, in the meaning defined at transitive sense

Kids Definition

activate

verb

ac·​ti·​vate ˈak-tə-ˌvāt 

activated; activating

1

: to make active

2

: to make (as molecules) more chemically active

3

: to make (a substance) give off radioactive particles, give off light at low temperatures, be easily affected by light, or carry an electric charge under the influence of light or other electromagnetic radiation

4

: to treat (as carbon or alumina) so as to improve the amount of adsorption

5

: to place on active military duty

activate the reserves

activation

ˌak-tə-ˈvā-shən 

noun

activator

ˈak-tə-ˌvāt-ər 

noun

Medical Definition

activate

transitive verb

ac·​ti·​vate ˈak-tə-ˌvāt 

activated; activating

: to make active or more active: as

a

: to convert into a biologically active derivative or form

activated plasminogen

b

: to make biologically or molecularly active

activate protein synthesis

The [spinal] cord also contains neuronal circuits … that can be activated by incoming sensory signals without input from the brain …

—John W. McDonald et al., Scientific American

c

: to make (a substance) radioactive

activation

ˌak-tə-ˈvā-shən 

noun