Definition of impulse in US English:



  • 1A sudden strong and unreflective urge or desire to act.

    ‘I had an almost irresistible impulse to giggle’
    • ‘His skin was almost translucent, and for a moment I longed to reach up and touch it, but I quickly pushed the impulse aside.’
    • ‘Isn't the real problem indeed that such people lack the ability to control their irrational desires and impulses?’
    • ‘I feel torn between two conflicting impulses - my desire to be taken seriously as an intellectual, and my desire to share with others the absurd things that delight me.’
    • ‘Most of the stuff I post on the site is the result of acting quickly on random impulses, and this was a case in point.’
    • ‘My first impulse was to get away from him as quickly as possible, but sometimes that is not easy to do.’
    • ‘People frequently say how much they really enjoy classical music or how they'd ‘really like to go to the symphony sometime’ but often fail to act on that impulse.’
    • ‘For a moment he had an impulse to confess, if for no other reason than to hear the detective tell him he'd done nothing wrong.’
    • ‘In order to lead a virtuous life, reason must shape our impulses and guide their expression in action.’
    • ‘Driven by a mad impulse, I strolled up to the road in front of the cab, and stood before it.’
    • ‘Often, persons with low frustration tolerance experience a strong impulse to escape from, or avoid frustrating situations.’
    • ‘You have forgotten all your nervousness and butterflies, and you are just acting on impulses.’
    • ‘This novel incorporates the full spectrum of what it means to be human, stripping away society to reveal the basic elements, impulses and desires of humanity.’
    • ‘I had a sudden impulse to tell the woman pouring the wine that I loved her.’
    • ‘If people are inherently bad, then their impulses, desires, and drives are inherently bad and must be resisted, controlled, or punished.’
    • ‘Bergman wants to portray the powerful, often destructive desires and impulses lying beneath placid social exteriors.’
    • ‘He adds, ‘The impulse to hoard, along with selfishness generally, is in my view inherent in human nature.’’
    • ‘At the same time, parenting skills are supposed to have improved as adults became better at mastering their own impulses and at developing strong emotional ties.’
    • ‘He nodded, successfully resisting the sudden impulse to reach for her hand.’
    • ‘Our reflective capacities allow us and require us to step back from our mere impulses in order to determine when and whether to act on them.’
    • ‘High emotional tension can produce sudden impulses in your behavior that cause difficulties.’
    urge, instinct, drive, compulsion, need, itch
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    1. 1.1 The tendency to act impulsively.
      ‘he was a man of impulse, not premeditation’
      spontaneity, impetuosity, wildness, recklessness, irresponsibility, rashness
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  • 2A driving or motivating force; an impetus.

    ‘an added impulse to this process of renewal’
    • ‘The individual provides the impulse which sets the process of litigation in motion, but the institution - the law - defines the terms.’
    • ‘They're not complying with international law and at the very moment in which we are trying to give a new impulse to the peace process.’
    • ‘Trade and distribution provided the central impulses for industrialization.’
    • ‘Indian thought transformed not only China and Southeast Asia, it may also have provided key impulses to Western thought.’
    • ‘It is no exaggeration to say that the territorial imperative has been the main impulse driving the aggressive behavior of nation-states.’
    • ‘One of the main impulses for devolution in the 1980s and 1990s was the need to defend the social democratic settlement in Scotland and Wales from the neo-liberal attack.’
    • ‘Moreover, the main impulses for change are internal, rather than the significantly more unpredictable external challenges of governing.’
    • ‘Neither do you disown a book that provided ideas and impulses to a generation of political science professionals.’
    • ‘Even so, in this process the educated must provide the initial impulse; they must make the masses conscious of themselves and of their destiny.’
    • ‘The authors would first like to thank Richard Swedberg, who provided the impulse to the present work, and continued to be a great source of inspiration on Schumpeter.’
    inspiration, stimulation, stimulus, incitement, motivation, encouragement, fillip, spur, prod, catalyst
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  • 3A pulse of electrical energy; a brief current.

    ‘nerve impulses’
    ‘a spiral is used to convert radio waves into electrical impulses’
    • ‘Nerve impulses are transmitted at synapses by the release of chemicals called neurotransmitters.’
    • ‘Serotonin is a neuro-transmitter - a chemical messenger - that helps transmit electrical impulses from one nerve ending to another.’
    • ‘The modules will be linked to existing retinal nerves that will send electrical impulses to the brain for processing.’
    • ‘A neuron generates an electrical impulse, causing the cell to release its neurotransmitters.’
    • ‘The inner ear then contains hair cells that respond to the fluid movement and then generate an electrical impulse that goes to the brain.’
    • ‘Implanted osteogenic stimulators deliver electrical impulses directly to the site where bone regrowth needs to occur.’
    • ‘Neurotransmitters are the chemicals used by the nervous system to transmit nerve impulses to and from the brain.’
    • ‘The microphone transmits sound to the implant, which converts it to electrical impulses that travel the thin wires and stimulate the auditory nerve.’
    • ‘The shapes of the waves show how well the heart's electrical impulses are working, the size of the heart, and how well the individual components of the heart are working together.’
    • ‘Nerve impulses created by this process travel to the brain via the optic nerve.’
    • ‘Removing the cat's cortex guaranteed that there would be no neural impulses from its higher brain.’
    • ‘Using this device he was able to show that the currents traveling through nerves and muscles were in the form of small, brief electrical impulses that we now call action potentials.’
    • ‘Signals are transmitted around the nervous system, along the fibres of nerve cells, in the form of electrical impulses called action potentials.’
    • ‘The stimulator provides impulses along the dorsal column spinal cord which in turn sets up paraesthesia from nerve pathways.’
    • ‘The modules will be linked to retinal nerves that will then send electrical impulses to the brain for processing.’
    • ‘The nature of nerve impulses, however, differs entirely from electromagnetic waves and sound waves.’
    • ‘These electrical signals send electrical impulses across the skin to an implanted receiver/stimulator in the shoulder to the electrode leads in the arm and hand.’
    • ‘The alpha and beta pathways typically allow for directed impulse conduction through the AV node.’
    • ‘Like most alkaloids, nicotine exerts its effects at receptors for chemicals that transmit nerve impulses.’
    • ‘Unlike its electrical predecessor, an optical switch does not convert the signal to an electrical impulse before directing it.’
    pulse, current, wave
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  • 4Physics
    A force acting briefly on a body and producing a finite change of momentum.

    • ‘I felt an impulse on the racket as a force reflected off the strings.’
    • ‘This hypothesis has been around for decades and the study of it has failed to generate enough positive data to lead us to believe that sound waves instead of ion flux is how impulses are generated.’
    • ‘Tesla recreated the Hertz experiment and quickly realised that an oscillator that he developed transmitted wireless impulses much more efficiently.’
    • ‘The process of minimizing an impact force can be approached from the definition of the impulse of force.’
    • ‘This will open the door for the realization that man exists within a huge field of gravitational and magnetic impulses.’
    1. 4.1 A change of momentum so produced, equivalent to the average value of the force multiplied by the time during which it acts.
      • ‘The average force and impulse of impact was found to be 1025 N and 11.0 N / s, respectively.’
      • ‘The impulse had a value of 1, and the highest peak in the response is less than 0.25, falling rapidly to tiny values.’
      • ‘Specific impulse equals thrust multiplied by the time over which the thrust acts.’
      • ‘Ion engines can attain specific impulses of tens of thousands of seconds.’
      • ‘The statistically nonzero impulses and the response multipliers are in Table 3.’


  • on impulse (or on an impulse)

    • Suddenly and without forethought; impulsively.

      • ‘On impulse, I quickly leaned over and kissed him before getting out of the vehicle.’
      • ‘Before you are allowed to place a bet there is a message asking you to confirm your bet so you are less likely to act on impulse.’
      • ‘I wonder if he really did act on an impulse, or if there's more to it?’
      • ‘He very rarely acts on impulse, but ever since Evelyn died, his emotions have been askew.’
      • ‘He had health worries and was short of money but had acted on impulse to provide the children with something he had promised them.’
      • ‘Mary Queen of Scots was recorded as very tall and beautiful but with a fiery temperament that often caused her to act on impulse and brought forth criticisms of tactlessness.’
      • ‘I stared at him for a moment, and then, acting completely on impulse, I pulled his head down and kissed him.’
      • ‘It's imperative that you don't act on impulse during this period, and that you think through the consequences of your actions.’
      • ‘Purely on impulse I leaned forward, my eyes closing of their own accord as Winter tilted her head up just a fraction.’
      • ‘Maybe I should try acting on impulse, instead of thinking so much.’
      impulsively, spontaneously, on the spur of the moment, without forethought, without planning, without thinking twice, without premeditation, unpremeditatedly
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Early 17th century (as a verb in the sense ‘give an impulse to’): the verb from Latin impuls- ‘driven on’, the noun from impulsus ‘impulsion’, both from the verb impellere (see impel).