Definition of activate in English:



  • 1Make (something) active or operative.

    ‘fumes from cooking are enough to activate the alarm’
    • ‘When part levels get low at a particular station, the operator activates a radio-frequency signal which causes a paper parts order slip to be generated in the marketplace.’
    • ‘Upon the application of Tc, the TetR repressor molecules are released from the tet operators and transcription is activated.’
    • ‘My telescope gathers about 2,000 times as much light as the unaided eye, enough to activate the cone cells in the human retina, so some color appears.’
    • ‘If this is not enough to activate an alliance, what is?’
    • ‘As I was walking back, she saw me and went to roll down the window but hit the door lock by mistake thus activating the car alarm.’
    • ‘It automatically inflates within three to five seconds of immersion in water or can be operated manually by activating a ripcord or by self-inflating.’
    • ‘It is almost impossible to deliver an inappropriate shock with an AED because the machine will allow the operator to activate the control only if an appropriate arrhythmia is detected.’
    • ‘Although the windows were not linked to the burglar alarm, a sensor activated the system and a passing police patrol stopped to check the building.’
    • ‘Last week we had our first serious tornado watch with afternoon skies gone dark enough to activate the street lamps.’
    • ‘Now, the state has activated its emergency operation center, saying at a level of one to five, it is now at a level of three.’
    • ‘The thieves escaped empty handed after the van's alarm was activated.’
    • ‘The component also enables the operator to set tolerance limits for important operating parameters, and activates an alarm when deviation from these ranges occurs.’
    • ‘One of the men had climbed through the parcel hatch and told her to keep away from the alarm button but she activated it as they left and saw they had a fourth man as a getaway driver outside.’
    • ‘Although we could use a lot more rain, most of our fields have had enough to activate the herbicides and early weed control generally has been good.’
    • ‘You'll thereby complete three to six sets per workout, more than enough to activate muscle fibers.’
    • ‘In Scotland, police were concerned enough to activate a nationwide intelligence centre to evaluate the terrorist threat north of the Border.’
    • ‘Her neighbours rushed in after Mrs Green activated the panic alarm she wears around her neck.’
    • ‘The alarm signal activates the receiver, which then plays the warning to everyone in earshot.’
    • ‘It's just a simple feedback operation: You click a switch that activates a set of relays that begin feeding electricity back to themselves, so they remain eternally on.’
    • ‘But this offering is not enough to activate our intellect.’
    • ‘This was the day the GSM operator activated its network and started selling prepaid cards to individual customers.’
    operate, switch on, turn on, start, start off, start up, set going, get going, trigger off, trigger, trip, set in motion, actuate, initiate, initialize, energize, animate
    View synonyms
    1. 1.1 Convert (a substance, molecule, etc.) into a reactive form.
      ‘activated chlorine’
      • ‘The specific biochemical reaction to glucagon involves activating a particular enzyme.’
      • ‘This molecule activates enzymes and other substances to help move fat out of fat cells and deliver it to active tissues (such as muscle fibers) that will burn it as fuel.’
      • ‘This results in a decrease in biological activity; but sulphonation is required to activate molecules as well.’
      • ‘This messenger in turn activates a so-called kinase, an enzyme that attaches phosphate groups to other proteins.’
      • ‘The energy that is required to activate molecules for a chemical reaction is the activation energy of the reaction.’