Definition of dual in English:


Line breaks: dual
Pronunciation: /ˈdjuːəl


  • 1 [attributive] Consisting of two parts, elements, or aspects: their dual role at work and home dual-language texts in English and Italian
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    • Inexperienced nurses usually remain in orientation for an average of five months - longer if they are expected to function in a dual role.
    • From the beginning his relationship with her has got this dual element to it.
    • These critics also recognize the dual aspects of decolonization.
  • 1.1 Grammar (In some languages) denoting an inflection that refers to exactly two people or things (as distinct from singular and plural).
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    • Yimas proper distinguishes four numbers in its pronominal paradigm (singular, dual, paucal, and plural) while Yimas Pidgin has only three.
    • It has dual number, so nouns and verbs must be learned in singular, dual, and plural.
    • Languages with dual markers have a different plural affix for sets of two than the affix for sets greater than two.
  • 1.2(In an aircraft) using dual controls: a dual flight
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    • You might want to consider scheduling an annual dual flight with an experienced instructor to review downwind take-offs and landings.
    • Schedule periodic dual flights when the crosswind exceeds your comfort level.
    • It would show the reaction of non flyers being taken on dual flights in incredible scenery.
  • 2 (often dual to) Mathematics (Of a theorem, expression, etc.) related to another by the interchange of particular pairs of terms, such as ‘point’ and ‘line’.
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    • He had proved that compact abelian groups are dual to discrete abelian groups, and von Neumann was interested in extending this result.


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  • 1 Grammar A dual form of a word.
  • 1.1 [mass noun] The dual number.
  • 2 Mathematics A theorem, expression, etc., that is dual to another.
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    • In fact this theorem is simply the dual of Pascal's theorem which was proved in 1639.
    • Because of the demands of differentiability in distribution theory, the spaces of test-functions and their duals are somewhat more complicated.

verb (duals, dualling, dualled)

[with object] British Back to top  
  • Convert (a road) into a dual carriageway: though there are no plans to dual the road, a public consultation on the A64 is set to start before the end of the year
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    • The answer is to double the capacity of the single carriageway, so the outer ring road is dualled all the way around.
    • But the major issue on the lips of many motorists, that of dualling the road, is not being addressed by Highways Agency chiefs.
    • Firstly, that it will have an effect on the Rillington bypass if the road is fully dualled and that will be a further setback for the people of Rillington.



(also dualise) verb
More example sentences
  • As a result, we have dualized spirituality and sexuality.
  • What gives the track the edge are the dualised male/female vocals.


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  • ‘The smart chip is dually engineered to prematurely register ink depletion and to render a cartridge unusable through the use of a built-in expiration date that is not revealed to the consumer,’ the suit said.
  • And the men in Almodóvar's films are dually endowed with ‘feminine’ and ‘masculine’ characteristics.
  • Specialized 12-step groups for persons dually diagnosed with substance abuse and mental health disorders also appear to be useful in encouraging abstinence and adherence to psychiatric medication.


late Middle English (as a noun denoting either of the two middle incisor teeth in each jaw): from Latin dualis, from duo 'two'.

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