n.
Function: adjective
Etymology: Late Latin binarius, from Latin bini two by two ― more at BIN-
Date: 1597
1 : compounded or consisting of or marked by two things or parts
2 a : DUPLE ― used of measure or rhythm b : having two musical subjects or two complementary sections
3 a : relating to, being, or belonging to a system of numbers having 2 as its base <the binary digits 0 and 1> b : involving a choice or condition of two alternatives (as on-off or yes-no)
4 a : composed of two chemical elements, an element and a radical that acts as an element, or two such radicals b : utilizing two harmless ingredients that upon combining form a lethal substance (as a gas) < binary weapons>
5 : relating two logical or mathematical elements <a binary operation>
6 : of or relating to the use of stable oppositions (as good and evil) to analyze a subject or create a structural model <the binary opposition of male and female ― Joan W. Scott>