# dual

> English word · Adjective · IPA /ˈd͡ʒuː.əl/ · frequency rank #4,443

## Definitions
1. Characterized by having two (usually equivalent) components.
2. Pertaining to two, pertaining to a pair of.
3. Pertaining to a grammatical number in certain languages that refers to two of something, such as a pair of shoes.
4. Exhibiting duality.
5. Being the space of all linear functionals of (some other space).
6. Being the dual of some other category; containing the same objects but with source and target reversed for all morphisms.

## Etymology
PIE word
 *dwóh₁
Borrowed from Latin dualis (“two”), from duo (“two”) + adjective suffix -alis.

## Easily confused with
- **due** (https://plainspell.com/en/vs/dual-vs-due)
- **duo** (https://plainspell.com/en/vs/dual-vs-duo)
- **dug** (https://plainspell.com/en/vs/dual-vs-dug)
- **dub** (https://plainspell.com/en/vs/dual-vs-dub)
- **duh** (https://plainspell.com/en/vs/dual-vs-duh)
- **DUI** (https://plainspell.com/en/vs/dual-vs-dui)
- **dun** (https://plainspell.com/en/vs/dual-vs-dun)
- **dum** (https://plainspell.com/en/vs/dual-vs-dum)
- **dup** (https://plainspell.com/en/vs/dual-vs-dup)
- **dud** (https://plainspell.com/en/vs/dual-vs-dud)
- **duc** (https://plainspell.com/en/vs/dual-vs-duc)
- **dur** (https://plainspell.com/en/vs/dual-vs-dur)
- **dude** (https://plainspell.com/en/vs/dual-vs-dude)
- **duty** (https://plainspell.com/en/vs/dual-vs-duty)
- **dumb** (https://plainspell.com/en/vs/dual-vs-dumb)
- **duke** (https://plainspell.com/en/vs/dual-vs-duke)
- **dust** (https://plainspell.com/en/vs/dual-vs-dust)
- **duck** (https://plainspell.com/en/vs/dual-vs-duck)
- **dump** (https://plainspell.com/en/vs/dual-vs-dump)
- **dull** (https://plainspell.com/en/vs/dual-vs-dull)

## Common misspellings (5)
`daul`, `ddual`, `duall`, `dula`, `udal`

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