n. [ L. dyas, dyadis, the number two. Gr. &unr_;: cf. F. dyade. See two, and cf. Duad. ]
a. (Chem.) Having a valence or combining power of two; capable of being substituted for, combined with, or replaced by, two atoms of hydrogen;
a. [ Gr. &unr_;, fr. &unr_; two. ] Pertaining to the number two; of two parts or elements. [ 1913 Webster ]
Dyadic arithmetic,