Word Confusion: Dual versus Duel

Plural for the noun: duals

Third person present verb: duals
Past tense or past participle: dualed [US], dualled [British] Present participle: dualing [US], dualling [British]

Plural for the noun: duels
Gerund: dueling [US], duelling [British]

Third person present verb: duels
Past tense or past participle: dueled [US], duelled [British] Ppresent participle: dueling [US], duelling [British]

• [Grammar; in some languages] Denoting an inflection that refers to exactly two people or things (as distinct from singular and plural)
• [In an aircraft] Using dual controls

[Mathematics; often dual to; of a theorem, expression, etc.] Related to another by the interchange of particular pairs of terms, such as point and line

Twofold

• Double

Noun:
[Grammar] A word or other form in the dual

• [Old English] Git (“you two”), as contrasted with ge (“you” referring to three or more)
• The dual number

[Geometry] Of a regular polyhedron with V vertices and F faces, the regular polyhedron having F vertices and V faces

[Mathematics] A theorem, expression, etc., that is dual to another

Verb, transitive:
[Civil Engineering; British] To make a road divided by a central strip of land, etc., with each side used by traffic moving in one direction

• [In modern use] A contest or race between two parties

Affair of honor

• Single combat
• [Sword] Fight, confrontation, face-off, shoot-out

Verb:
Fight a duel or duels

Their dual role at work and home is uncompromising.

Old English has dual numbers for first- and second-person pronouns.

I took the checkout to be an instructional flight, and logged it as dual time.

In mathematics, dual is a notion of paired concepts that mirror one another.

Duality is a correspondence between the properties of a category C and the dual properties of the opposite category C^op.

A dually truck is a standard pickup truck that has a set of double tires in the rear, enabling it to haul greater loads.

Noun:
Git, you two.

In a way, without vexing himself with the problem, he accepted their over-lordship of the world as dual.

The octahedron is the dual of the cube.

“. . . it is not in general true that applying the dual cone construction twice gives back the original set C” (Duality).

The set of all duals is a vector space called the dual space.

Verb, transitive:
They’re dualing the old single carriageway.

“I have to declare an interest and I do so with some ambivalence because if the road is dualled it is likely to take half of my front garden” (Parliamentary).

“The investment will allow Nexus to increase service frequencies, reduce journey times, and improve reliability by dualling three sections of line between Pelaw and South Shields” (Network).

He engaged in a chess duel with Kasparov.

Two eminent critics engaged in a verbal duel.

Verb:
They dueled with swords.

Serving officers have been forbidden to duel.

Aaron Burr challenged Alexander Hamilton to duel in angry response to Hamilton’s slander.

The original sense was single combat used to decide a judicial dispute, while the sense contest to decide a point of honor dates from the early 17th century.