/buy"neuh ree, -ner ee/ , adj., n., pl. binaries .
adj.
1. consisting of, indicating, or involving two.
2. Math.
a. of or pertaining to a system of numerical notation to the base 2, in which each place of a number, expressed as 0 or 1, corresponds to a power of 2. The decimal number 58 appears as 111010 in binary notation, since 58 = 1 × 2 5 + 1 × 2 4 + 1 × 2 3 + 0 × 2 2 + 1 × 2 1 + 0 × 2 0 .
b. of or pertaining to the digits or numbers used in binary notation.
c. of or pertaining to a binary system.
d. (of an operation) assigning a third quantity to two given quantities, as in the addition of two numbers.
3. Chem. noting a compound containing only two elements or groups, as sodium chloride, methyl bromide, or methyl hydroxide.
4. Metall. (of an alloy) having two principal constituents.
n.
5. a whole composed of two.
6. Astron. See binary star .
7. Also called binary number . Math. a number expressed in the binary system of notation.
[ 1350-1400; ME binarius, equiv. to bin ( i ) (see BIN-) + -arius -ARY ]