# duality

> English word · Noun · IPA /d(j)uːˈælɪti/ · frequency rank #24,432

## Definitions
1. A classification into two subclasses or opposed parts.
2. The interchangeability of points and planes.
3. The mathematical equivalence of two seemingly different theoretical descriptions of a physical system.

## Etymology
From Latin duālitās.
From dual + -ity.

## Easily confused with
- **Dalit** (https://plainspell.com/en/vs/dalit-vs-duality)
- **dualism** (https://plainspell.com/en/vs/dualism-vs-duality)

## Common misspellings (10)
`daulity`, `dduality`, `duailty`, `dualitty`, `dualityy`, `dualiyt`, `duallity`, `dualtiy`, `dulaity`, `udality`

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