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

For investors, the main concern will be her reputation for wanting spending to achieve growth and her penchant for central bank stimulus to goose the economy. —Jessica Coacci, Fortune, 4 Oct. 2025

To him, animal behavior was largely based on stimulus and response. —Danny Robb, JSTOR Daily, 1 Oct. 2025

Global consumer textile demand is affected by macroeconomic conditions, and the outlook for world GDP growth has been tepid since the benefits of stimulus faded with inflation and higher interest rates. —Sj Guest Editorial, Sourcing Journal, 26 Sep. 2025

Rumors and speculation have been floated on social media and unverified websites about a potential stimulus check being sent to Americans this year. —Shelby Slade, AZCentral.com, 26 Sep. 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