dyad

noun

1. A set of two elements treated as one; a pair.

   “[…] positing a dyad and constructing the infinite out of great and small, instead of treating the infinite as one, is peculiar to him; […]”

   “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. Two persons in an ongoing relationship; a dyadic relationship.

   “For each individual in a specific dyad (i.e., mother-offspring, offspring-father, sibling-sibling), […]”

3. The relationship or interaction itself in reference to a couple.
4. Any set of two different pitch classes.
5. An element, atom, or radical having a valence of or combining power of two.
6. A chromosome structure, usually X- or V-shaped, consisting of two condensed sister chromatids joined by a centromere.
7. A secondary unit of organisation consisting of an aggregate of monads.
8. A tensor of order two and rank one.