[ stim-yuh-luhs ]
/ ˈstɪm yə ləs /
Save This Word!
See synonyms for: stimulus / stimuli on Thesaurus.com

noun, plural stim·u·li [stim-yuh-lahy]. /ˈstɪm yəˌlaɪ/.
something that incites to action or exertion or quickens action, feeling, thought, etc.: The approval of others is a potent stimulus.
Physiology, Medicine/Medical. something that excites an organism or part to functional activity.
Smoothly step over to these common grammar mistakes that trip many people up. Good luck!
Question 1 of 7
Fill in the blank: I can’t figure out _____ gave me this gift.

Origin of stimulus

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


in·ter·stim·u·lus, noun, plural in·ter·stim·u·li.post·stim·u·lus, adjectivepre·stim·u·lus, noun, plural pre·stim·u·li.un·der·stim·u·lus, noun, plural un·der·stim·u·li.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


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.

Where does stimulus come from?

The first records of stimulus come from the 1600s. It comes from the Latin word stimulus, meaning “cattle prod”—a sharp stick used to poke cattle to get them to keep moving. In a general sense, that’s what a stimulus does—it prods something into action. What that action is varies depending on the context.

Scientifically speaking, a stimulus is anything that produces a response in an organism or in a cell or tissue of an organism. Such stimuli can be internal or external. Internal stimuli come from inside an organism—pain and hunger are internal stimuli. In humans, an external stimulus is anything that’s detected by the senses—light, noises, things we feel on our skin. Parents are often told to avoid having newborn babies around too many stimuli (like bright lights and colors and music) at once so that they don’t become overstimulated (overwhelmed by all the sensory input). In psychology, the term stimulus is often used in the context of conditioned responses—like the famous example of Pavlov’s dogs salivating at the sound of a bell. In this case, one stimulus (the sound of the bell) became associated with another (the presentation of food).

An economic stimulus is a government’s attempt to jump-start an economy, usually when it’s in a recession (a lengthy downturn). The U.S. government’s stimulus plan in response to the 2020 coronavirus pandemic, for example, ordered the distribution of stimulus payments in the form of stimulus checks to individual citizens with income under a certain level. The money from such checks is intended to serve as emergency financial relief in a time of high unemployment. But it’s also intended to help stimulate the economy by allowing (and encouraging) people to keep buying things. The hope is that more people buying things will allow more businesses to employ more people, which will boost economic recovery.

Not all stimulus measures involve sending money directly. The phrase stimulus package typically refers to a whole bundle of government policies meant to stimulate the economy in some way, including tax breaks, interest limits, and other actions, perhaps in addition to payments. During the recession in 2008, the U.S. government issued temporary tax cuts to certain households and businesses with the goal of economic stimulus.

The word bailout is sometimes associated with economic stimulus, but it has a narrower meaning. A bailout involves the government providing money to a company or institution that would fail or go bankrupt otherwise.

Stimulus can also be used in a more general way to refer to anything that acts as motivation or an incentive. For example, giving kids an allowance might be a stimulus to get them to do their chores.

Did you know ... ?

What are some other forms related to stimulus?

  • stimuli (plural)
  • interstimulus (noun)
  • poststimulus (adjective)
  • prestimulus (noun)
  • understimulus (noun)

What are some synonyms for stimulus?

What are some words that share a root or word element with stimulus


What are some words that often get used in discussing stimulus?

How is stimulus used in real life?

Stimulus is mostly used in a technical way in the contexts of science or finance, in which it has very different meanings.



Try using stimulus!

In which of the following situations is the economic sense of stimulus MOST likely to be used?

A. a recession
B. a strong economy
C. a very brief economic downturn
D. a bull market

How to use stimulus in a sentence

British Dictionary definitions for stimulus

/ (ˈstɪmjʊləs) /

noun plural -li (-ˌlaɪ, -ˌliː)
something that stimulates or acts as an incentive
any drug, agent, electrical impulse, or other factor able to cause a response in an organism
an object or event that is apprehended by the senses
med a former name for stimulant

Word Origin for stimulus

C17: from Latin: a cattle goad
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

Scientific definitions for stimulus

[ stĭmyə-ləs ]

Plural stimuli (stĭmyə-lī′)
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.
Something that has an impact or an effect on an organism so that its behavior is modified in a detectable way. See more at classical conditioning.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for stimulus


plur. stimuli (stim-yuh-leye)

An action, condition, or person that provokes a response, especially a conditioned response.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.