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

The factory is a throwback to a pre-Rust Belt America, providing ~200 jobs, endless pride, and a stimulus that benefits the rest of the local economy. —Katherine Laidlaw, HubSpot, 5 Sep. 2025

Miran has been critical of the Fed in the past, specifically taking issues with its aggressive stimulus during the Covid crisis. —Yun Li, CNBC, 3 Sep. 2025

In 2022, the British prime minister backed a mini-budget featuring a raft of unfunded fiscal stimulus, spooking the City to the extent that the pound spiraled to its lowest value ever against the dollar. —Eleanor Pringle, Fortune, 2 Sep. 2025

Using a mouse model lacking the Cntnap2 gene, scientists recorded heightened activity in the RTN when animals faced stimuli such as light flashes or air puffs. —Aamir Khollam, Interesting Engineering, 1 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