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

---

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.

---

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

Future work may help clarify how genetics, development, life experiences, and environment interact to shape the brain systems involved in reward-seeking, impulse control, and antisocial behavior.

From Science Daily • May 10, 2026

An omen among omens: Mid-dog-walk that day, I spot a onesie that reads “Milk Drunk” and shudder at the impulse to recruit our newborns into low-key bacchanalia.

From Slate • May 10, 2026

One common impulse, in which I take part, if insufficiently and awkwardly, is to give someone food or money, or call 911 when someone clearly needs help.

From Los Angeles Times • May 5, 2026

“There has been enough of an inflationary impulse in the system to have closed the window for central banks to simply look through the shock,” said Paul Hollingsworth, an economist at BNP Paribas.

From The Wall Street Journal • Apr. 30, 2026

When he did not reply, Naomi’s first impulse was to find the quickest way to send Beto back to the house.

From "Out of Darkness" by Ashley Hope Pérez

Related Words

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