stimulus

American  

[stim-yuh-luhs] / ˈstɪm jə ləs /

noun

• stimuli
  plural

1. something that incites to action or exertion or quickens action, feeling, thought, etc..

   The approval of others is a potent stimulus.

   Synonyms:

   provocation, motive, enticement, incitement

   Antonyms:

   discouragement

2. Physiology, Medicine/Medical. something that excites an organism or part to functional activity.

   Synonyms:

   stimulant

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stimulus British  

/ ˈstɪmjʊləs /

noun

1. something that stimulates or acts as an incentive

2. any drug, agent, electrical impulse, or other factor able to cause a response in an organism

3. an object or event that is apprehended by the senses

4. med a former name for stimulant

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stimulus Scientific  

/ stĭm′yə-ləs /

• stimuli
  plural

1. Physiology Something that can elicit or evoke a physiological response in a cell, a tissue, or an organism. A stimulus can be internal or external. Sense organs, such as the ear, and sensory receptors, such as those in the skin, are sensitive to external stimuli such as sound and touch.

2. Something that has an impact or an effect on an organism so that its behavior is modified in a detectable way.

3. See more at classical conditioning

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stimulus Cultural  

1. plur. stimuli (stim-yuh-leye) An action, condition, or person that provokes a response, especially a conditioned response.

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Usage

What does stimulus mean? In general, a stimulus is something that provokes or causes an action or response, as in Failing that test was the stimulus I needed to start studying harder. The plural of stimulus is stimuli. Its verb form is stimulate, which typically means to spur into action or to invigorate. In the context of science, a stimulus is anything that makes an organism or a part of an organism react in some way. For example, for most plants, sunlight acts as a stimulus that causes (stimulates) them to grow or move toward it. In economics, a stimulus is an injection of money into an economy by a government that’s intended to spur (stimulate) economic growth. This can take many forms, such as giving money directly to citizens via stimulus checks. In this sense, stimulus is usually used in the singular, especially in phrases like economic stimulus, stimulus package, and stimulus plan. Example: Congress has passed an unprecedented stimulus package in response to the 2020 coronavirus pandemic in the hopes of stimulating the economy at a time when so many people have lost income due to being out of work.

Other Word Forms

Derived Forms

• interstimulus
  noun
• prestimulus
  noun
• understimulus
  noun
• poststimulus
  adjective

Inflected Forms

Nouns

• stimuli
  plural

Etymology

Origin of stimulus

First recorded in 1605–15; from Latin: “a goad”

Explanation

A stimulus causes an action or response, like the ringing of your alarm clock if you didn't sleep through it. Stimulus is a word often used in biology — something that causes a reaction in an organ or cell, for example. In financial and economic contexts, a stimulus may be an incentive: the money you spend on your membership is a stimulus for hitting the gym. Though it can be a synonym for stimulant, they are not always used interchangeably. A stimulant is often a chemical or drug that increases activity — think caffeine. For more than one stimulus, use stimuli, not stimuluses.

Example Sentences

See Examples For:

stimulus stimuli

“Gradually removing monetary stimulus remains appropriate,” it said.

From The Wall Street Journal ● Sep. 2, 2026

The decline continued into the early 2020s because the stimulus checks and more generous unemployment insurance payments the government provided at the height of the COVID-19 pandemic helped keep millions of U.S. consumers afloat.

From Salon ● Aug. 29, 2026

In 2008, then Fed Chair Ben Bernanke started the bond-buying program known as “Operation Twist,” which subsequently provided a stimulus boost for the U.S. economy.

From MarketWatch ● Aug. 27, 2026

“Despite the goal with these incentives being to attract filmmaking and lead to economic stimulus, that’s not materialized in the data,” Button said.

From Los Angeles Times ● Aug. 5, 2026

He seemed to have lost the power of intellectual effort, now that the stimulus of pain had been removed.

From "1984" by George Orwell

Yet Schoenbrun’s observations are presented in the film as though they’re opaque, overloaded with smug surrealism and jam-packed with visual stimuli designed to wink and nudge at the otherwise obvious.

From Salon ● Aug. 26, 2026

The work could help scientists create metallocene-based materials with adjustable or stimuli responsive properties, potentially leading to new advances in chemistry, materials science, and medicine.

From Science Daily ● May 22, 2026

At the hospital, one of the officers requested that Cervantes submit to a “subjective sobriety test” that included measuring her eye’s response to stimuli, according to the complaint.

From Los Angeles Times ● Apr. 7, 2026

The ultralow rates, along with other government stimuli and zero-commission trades, kindled a new generation’s interest in the markets.

From The Wall Street Journal ● Jan. 13, 2026

He seemed unresponsive to normal stimuli, sealed off in his own world.

From "Newjack: Guarding Sing Sing" by Ted Conover

Related Words

• catalyst
• encouragement
• fillip
• impetus
• incentive
• motivation
• stimulant
• stimulation