# impetus

> English word · Noun · IPA /ˈɪm.pə.təs/ · frequency rank #20,388

## Definitions
1. Anything that impels; a stimulating factor.
2. A force, either internal or external, that impels; an impulse.
3. The force or energy associated with a moving body; a stimulus.
4. A principle of motive force, held as equivalent to weight times velocity by John Buridan, in an auxiliary theory of Aristotelian dynamics introduced by John Philoponus, describing projectile motion against gravity as linear until it transitions to a vertical drop and the intellectual precursor to the concepts of inertia, momentum and acceleration in classical mechanics.
5. An activity in response to a stimulus.

## Etymology
Borrowed from Latin impetus (“a rushing upon, an attack, assault, onset”), from impetō (“to rush upon, attack”), from in- (“upon”) + petō (“to seek, fall upon”).

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

## Common misspellings (10)
`imeptus`, `immpetus`, `impetsu`, `impettus`, `impetuss`, `impeuts`, `imppetus`, `impteus`, `ipmetus`, `mipetus`

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