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impulse

American  
[im-puhls] / ˈɪm pʌls /

noun

  1. the influence of a particular feeling, mental state, etc..

    to act under a generous impulse; to strike out at someone from an angry impulse.

  2. sudden, involuntary inclination prompting to action.

    to be swayed by impulse.

  3. an instance of this.

  4. a psychic drive or instinctual urge.

  5. an impelling action or force, driving onward or inducing motion.

  6. the effect of an impelling force; motion induced; impetus given.

  7. Physiology. a progressive wave of excitation over a nerve or muscle fiber, having either a stimulating or inhibitory effect.

  8. Mechanics. the product of the average force acting upon a body and the time during which it acts, equivalent to the change in the momentum of the body produced by such a force.

  9. Electricity. a single, usually sudden, flow of current in one direction.


adjective

  1. marked by or acting on impulse.

    an impulse buyer.

  2. bought or acquired on impulse.

    To reduce expenses, shun impulse items when shopping.

impulse British  
/ ˈɪmpʌls /

noun

  1. an impelling force or motion; thrust; impetus

  2. a sudden desire, whim, or inclination

    I bought it on an impulse

  3. an instinctive drive; urge

  4. tendency; current; trend

  5. physics

    1. the product of the average magnitude of a force acting on a body and the time for which it acts

    2. the change in the momentum of a body as a result of a force acting upon it for a short period of time

  6. physiol See nerve impulse

  7. electronics a less common word for pulse 1

  8. spontaneously or impulsively

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

impulse Scientific  
/ ĭmpŭls′ /
  1. A sudden flow of electrical current in one direction.

  2. An electrical signal traveling along the axon of a neuron. Nerve impulses excite or inhibit activity in other neurons or in the tissues of the body, such as muscles and glands.

  3. The change of momentum of a body or physical system over a time interval in classical mechanics, equal to the force applied times the length of the time interval over which it is applied.


Etymology

Origin of impulse

First recorded in 1640–50; from Latin impulsus “incitement, pressure,” noun use of past participle of impellere “to strike against, set in motion”; impel

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

"That was just the impulse for all of us to dream big."

From Barron's

But accepting that “where they are” is a degraded information ecosystem designed to reward the worst impulses in human nature means admitting that there is no possibility of rebuilding something more substantive.

From Salon

That means there’s something to be pondered in the widespread impulse among the “Ted Lasso” faithful to replay the entire season right after they’ve seen it for the first time.

From Salon

I’ve been spending a lot of time wondering where this new impulse comes from.

From The Wall Street Journal

On impulse, one of the men went inside for a shovel, and he and his friend began digging up sidewalk stones with the idea of making a little garden.

From The Wall Street Journal