(astronomy) any of the nine large celestial bodies in the solar system that revolve around the sun and shine by reflected light; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in order of their proximity to the sun; viewed from the constellation Hercules, all the planets rotate around the sun in a counterclockwise direction
any celestial body (other than comets or satellites) that revolves around a star
consisting of two (units or components or elements or terms) or based on two; "a binary star is a system in which two stars revolve around each other"; "a binary compound"; "the binary number system has two as its base"
of or pertaining to a number system have 2 as its base; "a binary digit"
a grammatical number category referring to two items or units as opposed to one item (singular) or more than two items (plural); "ancient Greek had the dual form but it has merged with the plural form in modern Greek"