[ 'bʌɪnəri ]
■ 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 ~ 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'.