# dyad

dy·ad- two units regarded as one; pair
- Biol. a double chromosome resulting from the division of a tetrad in meiosis; half of a tetrad
- Chem. an atom, element, or radical with a valence of two
- Sociology two persons in a continuing relationship involving interaction

Origin of dyad

Late Latin*dyas*(gen.

*dyadis*) from Classical Greek from

*dyo*, two

consisting of two

## dyad

noun

- Two individuals or units regarded as a pair:
*the mother-daughter dyad.* -
*Biology*One pair of homologous chromosomes resulting from the division of a tetrad during meiosis. -
*Mathematics***a.**A function that draws a correspondence from any vector**u**to the vector (**v·u**)**w**and is denoted**vw**, where**v**and**w**are a fixed pair of vectors and**v·u**is the scalar product of**v**and**u**. For example, if**v**= (2,3,1),**w**= (0,−1,4), and**u**= (*a,b,c*), then the dyad**vw**draws a correspondence from**u**to (2*a*+ 3*b*+*c*)**w**.**b.**A tensor formed from a vector in a vector space and a linear functional on that vector space.

adjective

Made up of two units.

Origin of dyad

*From*Greek

*duas*

*duad-*

*from*

*duo*

*two*; see

*dwo-*in Indo-European roots.

## dyad

Noun

(*plural* dyads)

Origin

From Ancient Greek *δύας* (dýas), *δύαδ-* (dýad-) from Ancient Greek *δύο* (dýo) from Ancient Greek *δύο* (duo), from Proto-Indo-European **duwó*,**duwéh₃* (**dwóh₁*). “dyad” in *The American Heritage® Dictionary of the English Language, Fourth Edition*, Houghton Mifflin Company, 2000.