dual

American  

[doo-uhl, dyoo-] / ˈdu əl, ˈdju- /

adjective

1. of, relating to, or noting two.

2. composed or consisting of two people, items, parts, etc., together; twofold; double.

   dual ownership;

   dual controls on a plane.

3. having a twofold, or double, character or nature.

4. Grammar. being or pertaining to a member of the category of number, as in Old English, Old Russian, or Arabic, that denotes two of the things in question.

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noun

Grammar.

1. the dual number.

2. a form in the dual, as Old English git “you two,” as contrasted with ge “you” referring to three or more.

dual British  

/ ˈdjuːəl /

adjective

1. relating to or denoting two

2. twofold; double

3. (in the grammar of Old English, Ancient Greek, and certain other languages) denoting a form of a word indicating that exactly two referents are being referred to

4. maths logic (of structures or expressions) having the property that the interchange of certain pairs of terms, and usually the distribution of negation, yields equivalent structures or expressions

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noun

1. grammar

   1. the dual number

   2. a dual form of a word

verb

1. (tr) to make (a road) into a dual carriageway

Other Word Forms

• dually
  adverb

Etymology

Origin of dual

First recorded in 1535–45; from Latin duālis “containing two, relating to a pair,” equivalent to du(o) two + -ālis -al ¹

Explanation

Dual means double, or having two elements. If you have a dual major, it means you're majoring in two subjects, like astronomy and microbiology. The adjective dual comes from the Latin duo, for two, and means having two parts. You can have a dual purpose, following two goals at once. To copilot an airplane, you need a cockpit with dual controls. If you're sometimes nasty and sometimes sugar sweet, people might think you have a dual personality. Don't confuse dual, though, with duel, which is a fight between two people.

Example Sentences

And on a team full of dual nationals who grew up overseas, he might have the unlikeliest background of anyone on the roster.

From The Wall Street Journal • Jun. 25, 2026

Around the time Corriveau and Corley were seeing traction with the early iteration of their dual restaurant-and-arcade concept, a cultural phenomenon rose in nascent techno and house scenes of cities from Detroit to Ibiza: raves.

From Slate • Jun. 25, 2026

Jesse Marsch, the U.S.-born coach who took over the national team in 2024, followed Herdman’s lead, recruiting six dual nationals to his World Cup team.

From Los Angeles Times • Jun. 19, 2026

Lumsden is to resign as North East MSP now that he has been elected for Aberdeen South because there is a Holyrood ban on dual mandates.

From BBC • Jun. 19, 2026

After a while, one actually succeeds in a dual role.

From "At Last She Stood" by Erin Entrada Kelly