# ounce

> English word · Noun · IPA /aʊns/ · frequency rank #9,642

## Definitions
1. An avoirdupois ounce, weighing ¹⁄₁₆ of an avoirdupois pound, or 28.349523125 grams.
2. A troy ounce, weighing ¹⁄₁₂ of a troy pound, or 480 grains, or 31.1034768 grams.
3. A US fluid ounce, with a volume of ¹⁄₁₆ of a US pint, 1.804688 cubic inches or 29.5735295625 millilitres.
4. A British imperial fluid ounce, with a volume of ¹⁄₂₀ of an imperial pint, 1.733871 cubic inches or 28.4130625 millilitres.
5. Any small amount, a little bit.

## Etymology
From Middle English ounce, unce, from Middle French once, from Latin uncia (“Roman ounce, various similar units”), ultimately from Proto-Indo-European *óynos (“one”). Doublet of a, one, inch, uncia, onça, onza, oka, ouguiya, and awqiyyah.

## Easily confused with
- **ounces** (https://plainspell.com/en/vs/ounce-vs-ounces)
- **oz** (https://plainspell.com/en/vs/ounce-vs-oz)
- **one** (https://plainspell.com/en/vs/one-vs-ounce)
- **once** (https://plainspell.com/en/vs/once-vs-ounce)
- **ouch** (https://plainspell.com/en/vs/ouch-vs-ounce)

## Common misspellings (6)
`onuce`, `oucne`, `ouncce`, `ounec`, `ounnce`, `uonce`

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