dyad Meaning, Definition & Usage

  1. noun two items of the same kind
    twosome; span; distich; couple; duo; twain; yoke; couplet; pair; duet; brace; duad.

WordNet

Dy"ad noun
Etymology
L. dyas, dyadis, the number two. Gr. : cf. F. dyade. See two, and cf. Duad.
Definitions
  1. Two units treated as one; a couple; a pair.
  2. (Chem.) An element, atom, or radical having a valence or combining power of two.
Dy"ad adjective
Definitions
  1. (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.

Webster 1913