English edit

Etymology edit

From Ancient Greek δυάς (duás), δυάδ- (duád-) from δύο (dúo, two), from Proto-Indo-European *duwó, *duwéh₃ (*dwóh₁).[1] The mathematics sense was coined by American scientist (1839–1903) Josiah Willard Gibbs in 1884 in the second half of his book Elements of Vector Analysis.

Pronunciation edit

Noun edit

dyad (plural dyads)

  1. A set of two elements treated as one; a pair.
    Synonyms: couple, duad; see also Thesaurus:duo
    • 1908, W. D. Ross, Metaphysics Book I, translation of original by Aristotle:
      [] positing a dyad and constructing the infinite out of great and small, instead of treating the infinite as one, is peculiar to him; []
    • 2019 January 29, Tom Bissell, “An Anti-Facebook Manifesto”, in New York Times[1]:
      McNamee describes their grip on the company as “the most centralized decision-making structure I have ever encountered in a large company.” Their power dyad is possible only because Facebook’s “core platform,” as McNamee puts it, is relatively simple: It “consists of a product and a monetization scheme.”
  2. (sociology) Two persons in an ongoing relationship; dyadic relationship.
    • 2003, Debra Lieberman, John Tooby, Leda Cosmides, The evolution of human incest avoidance mechanisms [] [2], page 20:
      For each individual in a specific dyad (i.e., mother-offspring, offspring-father, sibling-sibling), []
  3. (sociology) The relationship or interaction itself in reference to a couple.
  4. (music) Any set of two different pitch classes.
  5. (chemistry) An element, atom, or radical having a valence of or combining power of two.
  6. (biology) A chromosome structure, usually X- or V-shaped, consisting of two condensed sister chromatids joined by a centromere.
  7. (biology) A secondary unit of organisation consisting of an aggregate of monads.
  8. (mathematics) A tensor of order two and rank one.

Coordinate terms edit

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Translations edit

See also edit

References edit

  1. ^ “dyad”, in The American Heritage Dictionary of the English Language, 4th edition, Boston, Mass.: Houghton Mifflin, 2000, →ISBN.

Anagrams edit