source: By Cncplayer - Own work, CC BY-SA 3.0

1. relating to, composed of, or involving two things:

〖通例名詞の前で〗2つの, 2つから成る; 〘化〙 二元の.

e.g. testing the so-called binary, or dual-chemical, weapons.

2. relating to, using, or expressed in a system of numerical notation that has 2 rather than 10 as a base.

〘数〙 2進法の

noun (plural binaries)

1. the binary system:

〘数〙 2進法

e.g. binary notation

e.g. the device is counting in binary.

2. something having two parts.

a binary star.

〘天〙 連星(系)(binary star)

late Middle English (in the sense ‘duality, a pair’): from late Latin binarius, from bini ‘two together’.