activate
verb
ac·ti·vate
ˈak-tə-ˌvāt 
activated; activating
: 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
: to become active
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
The moon activating Neptune puts you in daydream mode.
—
Usa Today, USA Today, 26 Oct. 2025
The fat overload in astrocytes and microglia activates inflammatory pathways.
—New Atlas, 26 Oct. 2025
Officials in Jamaica have activated nearly 600 shelters and closed major transportation hubs in anticipation of hazardous conditions, and have said that warehouses across the island are well-stocked with thousands of food packages ready for quick distribution if necessary.
—Daniel Orton, MSNBC Newsweek, 26 Oct. 2025
Fortunately, the Mega’s automatic door release system activated in time, allowing the driver and passenger to escape unharmed.
—Bojan Stojkovski, Interesting Engineering, 26 Oct. 2025
See All Example Sentences for activate
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show current usage.
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Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
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Usa Today, USA Today, 26 Oct. 2025
The fat overload in astrocytes and microglia activates inflammatory pathways.
—New Atlas, 26 Oct. 2025
Officials in Jamaica have activated nearly 600 shelters and closed major transportation hubs in anticipation of hazardous conditions, and have said that warehouses across the island are well-stocked with thousands of food packages ready for quick distribution if necessary.
—Daniel Orton, MSNBC Newsweek, 26 Oct. 2025
Fortunately, the Mega’s automatic door release system activated in time, allowing the driver and passenger to escape unharmed.
—Bojan Stojkovski, Interesting Engineering, 26 Oct. 2025
See All Example Sentences for activate
Cite this Entry
“Activate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/activate. Accessed 31 Oct. 2025.
Copy CitationKids 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
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
John W. McDonald et al., Scientific American
c
: to make (a substance) radioactive
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