# fluid

> English word · Noun · IPA /ˈfluːɪd/ · frequency rank #4,946

## Definitions
1. Any substance which can flow with relative ease, tends to assume the shape of its container, and obeys Bernoulli's principle; a liquid, gas or plasma.
2. A liquid (as opposed to a solid or gas).
3. Intravenous fluids.

## Etymology
From Middle English fluid, from Latin fluidus (“flowing; fluid”), from Latin fluō (“to flow”), from Proto-Indo-European *bʰleh₁- (“to swell; surge; overflow; run”). Akin to Ancient Greek φλύειν (phlúein, “to swell; overflow”). Not related to English flow, which is a native, inherited word from *plew-, but is distantly related from English bleat.

## Easily confused with
- **fund** (https://plainspell.com/en/vs/fluid-vs-fund)
- **flux** (https://plainspell.com/en/vs/fluid-vs-flux)
- **found** (https://plainspell.com/en/vs/fluid-vs-found)
- **fruit** (https://plainspell.com/en/vs/fluid-vs-fruit)
- **flush** (https://plainspell.com/en/vs/fluid-vs-flush)
- **flute** (https://plainspell.com/en/vs/fluid-vs-flute)
- **flung** (https://plainspell.com/en/vs/fluid-vs-flung)
- **fluke** (https://plainspell.com/en/vs/fluid-vs-fluke)
- **flume** (https://plainspell.com/en/vs/fluid-vs-flume)
- **fluted** (https://plainspell.com/en/vs/fluid-vs-fluted)
- **flu** (https://plainspell.com/en/vs/flu-vs-fluid)
- **flip** (https://plainspell.com/en/vs/flip-vs-fluid)
- **fled** (https://plainspell.com/en/vs/fled-vs-fluid)
- **feud** (https://plainspell.com/en/vs/feud-vs-fluid)
- **flue** (https://plainspell.com/en/vs/flue-vs-fluid)
- **flood** (https://plainspell.com/en/vs/flood-vs-fluid)
- **Floyd** (https://plainspell.com/en/vs/floyd-vs-fluid)
- **flair** (https://plainspell.com/en/vs/flair-vs-fluid)
- **fluff** (https://plainspell.com/en/vs/fluff-vs-fluid)
- **flail** (https://plainspell.com/en/vs/flail-vs-fluid)

## Common misspellings (7)
`ffluid`, `fliud`, `flluid`, `fludi`, `fluidd`, `fulid`, `lfuid`

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