['b??n?ri]
¦ adjective
1. composed of or involving two things.
2. using or denoting a system of numerical notation with two as its base, employing the digits 0 and 1.
¦ noun (plural binaries)
1. the binary system of notation.
2. Astronomy a system of two stars revolving round their common centre.
Origin
ME (in the sense 'duality, a pair'): from late L. binarius, from bini 'two together'.