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

• incentive
• impetus
• encouragement
• motivation

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

State stimulus, on-demand infrastructure, affective consumption, and homegrown innovation are reshaping consumer expectations and fashion’s business logic. —Li Jun, Footwear News, 28 June 2025

That could reduce the urgency for Beijing to step up stimulus at the upcoming Politburo meeting in July, Xing added. —Anniek Bao, CNBC, 27 June 2025

But more than 20 years after Jeffrey Lawson's operation, an international research team found evidence that the brains of newborn premature babies react to pain stimuli in a very similar way to those of adults. —Christian Wolf, Scientific American, 25 June 2025

Nationwide, many schools are contending with falling enrollment as the birth rate declines, inflationary pressures, and the depletion of Covid-era stimulus funding that helped paper over problems in the aftermath of the pandemic. —Bloomberg, Mercury News, 25 June 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