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

Instead, Beijing rolled out a roughly $586 billion stimulus—equivalent to around 12 percent of China’s GDP in 2008—funneled almost entirely into infrastructure and construction. — Michael B. G. Froman, Foreign Affairs, 13 Aug. 2026

The gloves must be applied directly to someone's skin to deliver a pain stimulus that typically helps an officer gain compliance within seconds, according to the company. — CBS News, 12 Aug. 2026

The gloves must be applied directly to someone’s skin to deliver a pain stimulus that typically helps an officer gain compliance within seconds, according to the company. — Ryan J. Foley, Los Angeles Times, 12 Aug. 2026

Age is not just the reason behind change in football, but also the necessity to refresh and find a new stimulus. — Jacob Tanswell, New York Times, 11 Aug. 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