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
This will cover your first bet on an NFL Week 14 game to activate the $150 bonus or use the $1,000 safety net.
—
Tyler Everett, MSNBC Newsweek, 8 Dec. 2025
Using low-beam headlights, which also activate your taillights.
—Nc Weather Bot, Charlotte Observer, 7 Dec. 2025
Earlier in the week, the Steelers activated wide receiver Marquez Valdes-Scantling from the practice squad and signed veteran wide receiver Adam Thielen.
—Mike Darnay, CBS News, 7 Dec. 2025
In cases of near-zero visibility due to dense fog, activate your hazard lights and seek a safe spot, like a nearby business parking lot, to pull over and stop.
—Southern California Weather Report, Oc Register, 7 Dec. 2025
See All Example Sentences for activate
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Tyler Everett, MSNBC Newsweek, 8 Dec. 2025
Using low-beam headlights, which also activate your taillights.
—Nc Weather Bot, Charlotte Observer, 7 Dec. 2025
Earlier in the week, the Steelers activated wide receiver Marquez Valdes-Scantling from the practice squad and signed veteran wide receiver Adam Thielen.
—Mike Darnay, CBS News, 7 Dec. 2025
In cases of near-zero visibility due to dense fog, activate your hazard lights and seek a safe spot, like a nearby business parking lot, to pull over and stop.
—Southern California Weather Report, Oc Register, 7 Dec. 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 8 Dec. 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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share