Dyad
Dyad or dyade may refer to:

Arts and entertainment
Dyad (music), a set of two notes or pitches
Dyad (novel), by Michael Brodsky, 1989
Dyad (video game), 2012
Dyad 1909 and Dyad 1929, ballets by Wayne McGregor
Dyad Institute, a fictional biotech corporation in the Canadian TV series Orphan Black

Other uses
Dyad (biology), a pair of sister chromatids
Dyad (philosophy), used by the Pythagoreans for the number two, representing "twoness" or "otherness"
Dyad (sociology), a group of two people
Grizzled Young Veterans, also known as The Dyad, a British professional wrestling tag team

See also
Dyadic (disambiguation)
Diad, in cell biology
Dryad (disambiguation)
Dyad pedagogy, a goal-directed teaching method
Dyad symmetry, in genetics
Triad (disambiguation) ("group of 3")