# stimulus

> English word · Noun · IPA /ˈstɪm.jə.ləs/ · frequency rank #9,399

## Definitions
1. An external phenomenon that has an influence on a system, by triggering or modifying an internal phenomenon; for example, a spur or incentive that drives a person to take action or change behaviour.
2. Something external that elicits or influences a physiological or psychological activity or response, or that affects any of the sensory apparatuses.
3. A stinging part on the body of a plant or insect.

## Etymology
Borrowed from Latin stimulus (“goad, prick”).

## Easily confused with
- **stimuli** (https://plainspell.com/en/vs/stimuli-vs-stimulus)

## Common misspellings (12)
`sitmulus`, `sstimulus`, `stimluus`, `stimmulus`, `stimullus`, `stimulsu`, `stimuluss`, `stimuuls`, `stiumlus`, `stmiulus`, `sttimulus`, `tsimulus`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/stimulus