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.

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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

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impulse Scientific  

/ ĭm′pŭls′ /

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.

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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”; see impel

Explanation

An impulse is a sudden force or desire — this could be an electrical impulse, or an impulse to get some pizza. If you act on a sudden feeling or thought, you’re following an impulse. That's like a whim: an impulse isn't something you've given a lot of thought. Another meaning of impulse is an electrical charge or pulse. Electrical impulses are coursing through wires all through your house every day. Both kinds of impulses make things happen. The electrical impulse keeps the refrigerator going, and then you have an impulse to eat all the ice cream in the fridge.

Example Sentences

“The retail impulse to bid up these names definitely says something about risk appetite,” said Ross Mayfield, an investment strategist at Baird Private Wealth Management.

From MarketWatch • Apr. 22, 2026

The market’s current leap to new records reflects the same impulse to buy the dip that propelled stocks during the Covid-19 pandemic and last year’s tariff turmoil.

From The Wall Street Journal • Apr. 22, 2026

The impulse to dismiss all this as a detector company drumming up business runs into an issue—Pangram actually works way better than you might think.

From Slate • Apr. 17, 2026

He says he cooks chillis and stews to take to work, avoids impulse purchases and tries to keep spending on a night out below £20.

From BBC • Apr. 17, 2026

My interpretation of the definitions of specific impulse and mass ratio especially seemed to impress him.

From "October Sky" by Homer Hickam

Related Words

• desire
• feeling
• inclination
• influence
• instinct
• motivation
• motive
• notion
• passion
• thought
• whim
• wish