stimulus

noun

stim·​u·​lus ˈstim-yə-ləs 

plural stimuli ˈstim-yə-ˌlī  -ˌlē 

: something that rouses or incites to activity: such as

a

: incentive

b

: stimulant sense 1

c

: an agent (such as an environmental change) that directly influences the activity of a living organism or one of its parts (as by exciting a sensory organ or evoking muscular contraction or glandular secretion)

Synonyms

• boost
• encouragement
• goad
• impetus
• impulse
• incentive
• incitation
• incitement
• instigation
• momentum
• motivation
• provocation
• spur
• stimulant
• yeast

Examples of stimulus in a Sentence

The pay raise was a stimulus for production.

Heat and light are physical stimuli.

The dog responded to the stimulus of the ringing bell.

Recent Examples on the Web

This brain activity leads to the provocative conclusion that people with fibromyalgia don’t simply have lower thresholds for reporting a stimulus as painful. —Peter Ubel, Forbes.com, 26 Mar. 2025

In fact, leading economists agree that health care price transparency will free up $1 trillion in our economy every year, generating an enormous economic stimulus while reining in the runaway costs plaguing businesses nationwide. —Thomas G. Moukawsher, Newsweek, 22 Mar. 2025

Otherwise, the brain has to learn when typically scary stimuli are harmless and can be ignored. —Emilie Le Beau Lucchesi, Discover Magazine, 20 Mar. 2025

The last bitcoin price boom that saw the bitcoin price climb to around $70,000 in late 2021 came in the aftermath of huge Covid-era government stimulus spending and money-printing. —Billy Bambrough, Forbes, 19 Mar. 2025

Word History

Etymology

Latin

First Known Use

1684, in the meaning defined above

Rhymes for stimulus

• limulus

Kids Definition

stimulus

noun

stim·​u·​lus ˈstim-yə-ləs 

plural stimuli -ˌlī 

-ˌlē

1

: something that rouses or stirs to action : incentive

2

: something (as an environmental change) that acts to partly change bodily activity (as by exciting a sensory organ)

heat, light, and sound are common physical stimuli

Medical Definition

stimulus

noun

stim·​u·​lus ˈstim-yə-ləs 

plural stimuli -ˌlī  -ˌlē 

1

: stimulant sense 1

2

: an agent (as an environmental change) that directly influences the activity of living protoplasm (as by exciting a sensory organ or evoking muscular contraction or glandular secretion)

a visual stimulus