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

Wang, however, projects each of these choice from deep within, crafting a character who’s both uncomfortable with his reactions to people, emotions and external stimuli, but is, at this point in his life, also unfortunately used to his discomforts, and begrudgingly accepts them. —Siddhant Adlakha, Variety, 18 Mar. 2026

In 2022, the economy was still rebounding strongly from COVID, with the vestiges of a big fiscal stimulus at its back. —John Cassidy, New Yorker, 13 Mar. 2026

While intended as a pandemic-era stimulus program, the breakthrough measure was seen as boosting the euro’s status as reserve asset. —Jason Ma, Fortune, 13 Mar. 2026

Silence and Darkness Induces a Meditative State Sensory deprivation, the intentional removal of external stimuli like sounds or visuals (a la sitting in a coffin), can reduce brain stimulation and cause a state of deep relaxation. —Julia Ries Wexler, Outside, 12 Mar. 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