a natural body that revolves around a planet such as a moon
either of the two times a year when the sun is at its greatest distance from the celestial equator that takes place about June 21 and about December 22
the small circle of the celestial sphere whose plane is tangent to the earth at the position of the observer
the magnitude or brightness of a star as it appears to an observer on the earth
a celestial body with a mass of gas that is hot enough to produce and sustain nuclear fusion, thus producing luminosity
any of the small bodies, often remnants of comets, traveling through space: when such a body enters the earth's atmosphere it is heated to luminosity and becomes a meteor
1770, "line of separation between the bright and dark parts of a moon or planet," from L. terminator, from terminare (see terminus). Meaning "one who terminates (something)" is attested from 1846.
electronics A resistor connected to a signal wire in a bus or network for the purpose of impedance matching to prevent reflections. For example, a 50 ohm resistor connected across the end of an Ethernet cable. SCSI chains and some LocalTalk wiring schemes also require terminators. (1995-05-17)