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

The dangling carrot predates the conflict, introduced last year as a stimulus. —Kelsey Warner, semafor.com, 29 Apr. 2026

Beginning with the stimulus of a cup or two of strong coffee, fifteen-year-old Columbia College sophomore George Templeton Strong started a diary in 1835. —Matthew Wills, JSTOR Daily, 27 Apr. 2026

Marketing stimuli relates to actions planned and carried out by enterprises or institutions, whereas environmental stimuli include inputs occurring in the enlarged scenario and include social factors as well as economic, political, technological, and cultural dimensions. —Encyclopedia Britannica, 27 Apr. 2026

The project aims to produce materials that change their mechanical properties and shape in response to external light stimuli. —Aman Tripathi, Interesting Engineering, 25 Apr. 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