# effusion

> English word · Noun · frequency rank #58,656

## Definitions
1. A liquid outpouring.
2. Process of gases passing through a hole or holes considerably smaller than the mean free path of the gas molecules.
3. An outpouring of speech or emotion.
4. The seeping of fluid into a body cavity; the fluid itself.

## Etymology
Borrowed from Middle French effusion, from Latin effūsiō (“outpouring”). Displaced native Old English āgotennes.

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