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

Further stimulus is expected in the form of rate cuts from the Federal Reserve. —Eleanor Pringle, Fortune, 27 Oct. 2025

And yet, Democrats want to keep COVID-era stimulus checks flowing to insurers in perpetuity. —Sally C. Pipes, Boston Herald, 24 Oct. 2025

Our amygdala is overactive, our nervous systems are fried and our dopamine cycles are hijacked by short-term stimuli. —Chris Schembra, Rolling Stone, 22 Oct. 2025

These hybrid materials can reversibly change shape when exposed to different stimuli, thanks to the predictable nature of DNA pairing and the stability provided by inorganic components such as gold or graphene oxide. —Jijo Malayil, Interesting Engineering, 20 Oct. 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