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 of stimulus

• 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

There’s a lot of stimulus coming from the One Big Beautiful Bill. —Eleanor Pringle, Fortune, 14 Jan. 2026

With previous federal stimulus checks, individuals earning up to $75,000 and couples earning up to $150,000 received full payments. —Bebe Hodges, Cincinnati Enquirer, 13 Jan. 2026

There’s the stimulus from the One Big Beautiful Bill Act, the prospect of lower interest rates from a more dovish incoming Federal Reserve chair, and the benefits from artificial intelligence accruing to the real economy — major pillars maintaining a bullish outlook . —Sarah Min, CNBC, 2 Jan. 2026

By this decade, your body has started to naturally lose muscle mass, and putting on new muscle may be more difficult due to anabolic resistance, which blunts the muscle’s ability to respond to external stimuli like exercise and protein. —Emma Loewe, Outside, 1 Jan. 2026

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