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

It remains to be seen if Beijing will step up stimulus to shore up domestic growth in the near term, with policymakers instead focusing on executing existing policies.

From The Wall Street Journal ● Sep. 15, 2026

The three rounds of pandemic stimulus checks approved in 2020 and 2021 came to about $814 billion in total, according to federal oversight data.

From Barron's ● Sep. 10, 2026

That’s a hefty amount compared with the $1.8 trillion deficit the U.S. ran last year, which didn’t include any stimulus.

From MarketWatch ● Sep. 10, 2026

Despite rising calls for more stimulus, Beijing has held off on additional monetary easing, choosing instead to focus on accelerating the allocation of fiscal funds.

From The Wall Street Journal ● Sep. 7, 2026

The stimulus would lead inevitably to inflation, he thought, but also to a boom in stock prices.

From "The Big Short" by Michael Lewis

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

They employ all manners of external stimuli and self-optimization techniques to approach even a fraction of what your heart is naturally capable of.

From Los Angeles Times ● Jul. 23, 2026

By encoding these digital patterns within the hydrogel, the researchers can program how the smart skin reacts to different stimuli.

From Science Daily ● Feb. 6, 2026

Set aside all the academic debates about how many words a young child should hear; parents’ job is to expose their kids to stimuli that expand their thinking.

From The Wall Street Journal ● Dec. 19, 2025

What interruptions and stimuli rise to the surface even when were intent on focusing on something else?

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel

Related Words

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