German

Noun

Dual m ‎(genitive Duals, plural Duale)

1. (grammar) dual, dual number

Synonyms

• Dualis
• Zweizahl

English

Alternative forms

• (abbreviation, grammar): du.

Adjective

dual ‎(not comparable)

1. Exhibiting duality; characterized by having two (usually equivalent) components.
2. Acting as a counterpart.
3. Double.

   dual-headed computer

4. (grammar) Pertaining to grammatical number (as in singular and plural), referring to two of something, such as a pair of shoes, in the context of the singular, plural and in some languages, trial grammatical number. Modern Arabic displays a dual number, as did Homeric Greek.
5. (linear algebra) Being the space of all linear functionals of (some other space).
   • 2012, Doug Fisher, Hans-J. Lenz, Learning from Data: Artificial Intelligence and Statistics V, Springer Science & Business Media (ISBN 9781461224044), page 81

     Accordingly, a hyperplane in the sample space is dual to a subspace in the variable space.

6. (category theory) Being the dual of (some other category); containing the same objects but with domain and codomain reversed for all functions.
   • 1992, Colin McLarty, Elementary Categories, Elementary Toposes, Clarendon Press (ISBN 9780191589492), page 77

     Every category is dual to its own dual, so if a statement holds in all categories so does its dual.

Derived terms

• duality
• dualism

Synonyms

• (category theory): opposite

Translations

Noun

dual ‎(plural duals)

1. Of an item that is one of a pair, the other item in the pair.
2. (geometry) Of a regular polyhedron with V vertices and F faces, the regular polyhedron having F vertices and V faces.

   The octahedron is the dual of the cube.

3. (grammar) dual number The grammatical number of a noun marking two of something (as in singular, dual, plural), sometimes referring to two of anything (a couple of, exactly two of), or a chirality-marked pair (as in left and right, as with gloves or shoes) or in some languages as a discourse marker, "between you and me". A few languages display trial number.
4. (mathematics) Of a vector in an inner product space, the linear functional corresponding to taking the inner product with that vector. The set of all duals is a vector space called the dual space.

See also

• (grammatical numbers) grammatical number; singular, dual, trial, quadral, paucal, plural ^{(Category: en:Grammar)}
• unal
• duel

Translations

Anagrams

• auld
• laud
• udal

Irish

Pronunciation

• IPA^(key): /d̪ˠuəlˠ/

Etymology 1

From Old Irish dúal ‎(“tress, lock of hair”), from Proto-Celtic *doklo-, from Proto-Indo-European *doḱ-lo- (compare Icelandic tagl ‎(“horse’s tail”), Old English tægel, English tail).

Noun

dual m ‎(genitive singular duail, nominative plural duail)

1. lock, tress
2. wisp, tuft
3. ply, strand
4. twist, twine
5. spiral, whirl

Declension

Synonyms

• dlaoi ‎(“wisp, tuft; lock, tress”)
• dual gruaige ‎(“lock of hair”)

Derived terms

• dualach¹

Verb

dual ‎(present analytic dualann, future analytic dualfaidh, verbal noun dualadh, past participle dualta)

1. to twine
2. to braid, coil
3. to interlace, fold

Conjugation

Etymology 2

Noun

dual m ‎(genitive singular duail, nominative plural duail)

1. dowel
2. knot (in timber)

Declension

Synonyms

• (knot): alt, cranra

Derived terms

• dualach²
• dualbhata

Etymology 3

From Proto-Indo-European *dʰewgʰ-.

Adjective

dual

1. native, natural

   Is dual dó a bheith leisciúil.‎ ― He is naturally lazy.

2. proper, fitting
3. in the natural order of things
4. fated
5. possible

Declension

Mutation

Portuguese

Adjective

dual m, f ‎(plural duais, comparable)

1. dual (having two elements)

Scottish Gaelic

Noun

dual m ‎(genitive singular duail, plural dualan)

1. birthright

Synonyms

• còir-bhreith

Derived terms

• bu dual do dh'isean an ròin a dhol chun na mara

Noun

dual m ‎(genitive singular duail, plural dualan)

1. curl, lock of hair
2. plait, strand, braid, or fold
3. ringlet

Adjective

dual, comparative nas duaile

1. hereditary,
2. usual, natural

Spanish

Adjective

dual m, f ‎(plural duales)

1. dual
2. (grammar) dual