1) Being a group of two 2) Deuce 3) Of or consisting of a dyad 4) Pertaining to the number 2 
• (a.) Pertaining to the number two; of two parts or elements.
Dy·ad'ic adjective [ Greek ..., from ... two.] Pertaining to the number two; of two parts or elements. Dyadic arithmetic , 
[adj] - of or relating to a dyad or based on two
adjective of or relating to a dyad or based on two
(Gr. duas, two) Term meaning duality. Human experience is said to be dyadic, i.e. man's nature is dual in conflicts between good intentions and bad accomplishments, in oppositional strains and stresses. The personality of God is held to be dyadic in the confronting of difficulties or frustrations to his good will. Reality is spoken of as dyadic wh....
of or consisting of a dyad; being a group of two. · pertaining to the number 2.