Pertaining or relating to the number two, or to a dyad; consisting of two parts or elements: as, a dyadic metal.In Gr. pros.:Comprising two different rhythms or meters: as, a dyadic epiploce.Consisting of pericopes, or groups of systems each of which contains two unlike systems: as, a dyadic poem.Also dyad, duadic.n. In mathematics, a sum of dyads.n. The science of reckoning with a system of numerals in which the ratio of values of successive places is two.