BINARY

I. noun (plural -ries) Date: 15th century something made of or based on two things or parts: as, ~ star , a ~ number system, II. adjective see: bin- Date: 1597 compounded or consisting of or marked by two things or parts, 2. duple , having two musical subjects or two complementary sections, 3. relating to, being, or belonging to a system of numbers having 2 as its base , involving a choice or condition of two alternatives (as on-off or yes-no), 4. composed of two chemical elements, an element and a radical that acts as an element, or two such radicals, utilizing two harmless ingredients that upon combining form a lethal substance (as a gas) , relating two logical or mathematical elements , of or relating to the use of stable oppositions (as good and evil) to analyze a subject or create a structural model