Dual

4 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Dual \Du"al\, a. [L. dualis, fr. duo two. See {Two}.]
     Expressing, or consisting of, the number two; belonging to
     two; as, the dual number of nouns, etc., in Greek.
     [1913 Webster]
  
           Here you have one half of our dual truth. --Tyndall.


     [1913 Webster]

From WordNet (r) 2.0 [wn]:

  dual
       adj 1: consisting of or involving two parts or components usually
              in pairs; "an egg with a double yolk"; "a double
              (binary) star"; "double doors"; "dual controls for
              pilot and copilot"; "duple (or double) time consists
              of two (or a multiple of two) beats to a measure"
              [syn: {double}, {duple}]
       2: having more than one decidedly dissimilar aspects or
          qualities; "a double (or dual) role for an actor"; "the
          office of a clergyman is twofold; public preaching and
          private influence"- R.W.Emerson; "every episode has its
          double and treble meaning"-Frederick Harrison [syn: {double},
           {twofold}, {treble}, {threefold}]
       3: a grammatical number category referring to two items or
          units as opposed to one item (singular) or more than two
          items (plural); "ancient Greek had the dual form but it
          has merged with the plural form in modern Greek"

From Moby Thesaurus II by Grady Ward, 1.0 [moby-thes]:

  43 Moby Thesaurus words for "dual":
     Janus-like, ambidextrous, bifacial, bifold, biform, bifurcated,
     bilateral, binary, binate, biparous, bipartisan, bipartite,
     bivalent, conduplicate, dichotomous, disomatous, double,
     double-barreled, double-faced, duadic, dualistic, duple, duplex,
     duplicate, duplicated, dyadic, geminate, geminated, identical,
     matched, paired, second, secondary, twain, twin, twinned, two,
     two-faced, two-level, two-ply, two-sided, two-story, twofold
  
  

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  dual
       
           Every field of mathematics has a different
          meaning of dual.  Loosely, where there is some binary symmetry
          of a theory, the image of what you look at normally under this
          symmetry is referred to as the dual of your normal things.
       
          In linear algebra for example, for any {vector space} V, over
          a {field}, F, the vector space of {linear maps} from V to F is
          known as the dual of V.  It can be shown that if V is
          finite-dimensional, V and its dual are {isomorphic} (though no
          isomorphism between them is any more natural than any other).
       
          There is a natural {embedding} of any vector space in the dual
          of its dual:
       
              V -> V'': v -> (V': w -> wv : F)
       
          (x' is normally written as x with a horizontal bar above it).
          I.e. v'' is the linear map, from V' to F, which maps any w to
          the scalar obtained by applying w to v.  In short, this
          double-dual mapping simply exchanges the roles of function and
          argument.
       
          It is conventional, when talking about vectors in V, to refer
          to the members of V' as covectors.
       
          (1997-03-16)