Compounded or consisting of two things or parts; characterised by two (things). Binary arithmetic, that in which numbers are expressed according to the binary scale, or in which two figures only, 0 and 1, are used, in lieu of ten; the cipher multiplying everything by two, as in common arithmetic by ten. Thus, 1 is one; 10 is two; 11 is three; 100 is four, etc.
(Science: chemistry) binary compound, the theory that all chemical compounds consist of two constituents of opposite and unlike qualities.
Origin: L. Binarius, fr. Bini two by two, two at a time, fr. Root of bis twice; akin to E. Two: cf. F. Binaire.