• WordNet 3.6
    • n dyad two items of the same kind
    • ***
Webster's Revised Unabridged Dictionary
    • Dyad (Chem) An element, atom, or radical having a valence or combining power of two.
    • a Dyad (Chem) Having a valence or combining power of two; capable of being substituted for, combined with, or replaced by, two atoms of hydrogen; as, oxygen and calcium are dyad elements. See Valence.
    • Dyad Two units treated as one; a couple; a pair.
    • ***
Century Dictionary and Cyclopedia
    • n dyad Two units treated as one; a pair; a couple.
    • n dyad In chem., an elementary substance each of whose atoms, in combining with other atoms or molecules, is equivalent in saturating power to two atoms of hydrogen. For example, oxygen is a dyad as seen in the compound H2O (water), where one atom of oxygen combines with and saturates two atoms of hydrogen.
    • n dyad In morphology, a secondary unit of organization, resulting from individuation or integration of an aggregate of monads. See monad.
    • n dyad In mathematics, an expression signifying the operation of multiplying internally by one vector and then by another.
    • dyad Same as dyadic.
    • n dyad A group or association of two chromosomes in certain cells, such as the germ-cells in certain stages.
    • n dyad In prosody, a group of two lines having different rhythms.
    • dyad Noting an axis of twofold symmetry. See symmetry.
    • ***
Chambers's Twentieth Century Dictionary
    • n Dyad dī′ad a pair of units treated as one: :
    • n Dyad dī′ad (chem.) an atom, radical, or element having a combining power of two units
    • n Dyad dī′ad (biol.) a secondary unit of organisation consisting of an aggregate of monads
    • ***


Webster's Revised Unabridged Dictionary
L. dyas, dyadis, the number two. Gr. : cf. F. dyade,. See two, and cf. Duad


In literature:

Accordingly elements have been classed as monads, dyads, triads, etc.
"Scientific American Supplement, No. 324, March 18, 1882" by Various
This suggests that the elements, called by the chemists monads, dyads, triads and so on, consist of one, two, etc.
"Aether and Gravitation" by William George Hooper
In figure 130 one lagging chromosome shows the dyad nature of the products of the division of the tetrad.
"Studies in Spermatogenesis (Part 1 of 2)" by Nettie Maria Stevens
There being six pairs of parallel edges on an octahedron, there are consequently six dyad axes of symmetry.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7" by Various
What is to become two, must partake of the Dyad: what is to become one, of the Monad.
"Plato and the Other Companions of Sokrates, 3rd ed. Volume II (of 4)" by George Grote

In news:

Using a syncopated motorik beat as a baseline, Dyad makes the kind of electronic music with a seeming leg in '90s house that could well fill the synth-pop album that Aphex Twin never made.
Request feedback on Hospital implementation of new policies due t. Job Descriptions for Dyad Leadership Model.

In science:

Jij = Jij − (RiPj − Rj Pi ) Dij = Dij − (RiPj + Rj Pi ) , Similarly remove from the quadrupole and stress tensors the CM coordinate and momentum dyads.
Areal Theory
Yau, International Press Company, 157–223 (1994) [NR69] Nazarova, L.A., Roiter, A.V.: Finitely generated modules over a dyad of two local Dedekind rings, and finite groups with an Abelian normal divisor of index p.
Simple vector bundles on plane degenerations of an elliptic curve
AA = fA · pAA is the AA dyad probability, and so on.
Random copolymer adsorption: Morita approximation compared to exact numerical simulations
Beyond values depending on the sole distribution of symbols, one may consider pairs (dyads) or sequences of three (triads) adjacent outcomes.
Assessing Cognitive Randomness: A Kolmogorov Complexity Approach
In a truly (infinite) random sequence, any dyad should appear with the same probability.
Assessing Cognitive Randomness: A Kolmogorov Complexity Approach