dual

American  

[doo-uhl, dyoo-] / ˈdu əl, ˈdyu- /

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

Example Sentences

"We also noticed a dual effect of sorts," Araneda noted.

From Science Daily • Apr. 6, 2026

The entirety of the 10th floor is occupied by the palatial primary suite, which features its own spa-style bathroom, a sauna, a workout room, dual dressing rooms, as well as a private terrace.

From MarketWatch • Apr. 6, 2026

Last week in a Mission League dual meet against Sherman Oaks Notre Dame, he won with a time of 10.56.

From Los Angeles Times • Apr. 5, 2026

Ending dual citizenship would force me to choose between the country of my origin and the country of my parents’ origin.

From Salon • Apr. 4, 2026

When Dusya didn’t answer, Irina took over the dual controls.

From "A Thousand Sisters" by Elizabeth Wein