the small circle of the celestial sphere whose plane is tangent to the earth at the position of the observer
a zodiacal constellation between Virgo and Serpens also called the Balance
the particular appearance presented by the moon or a planet at a given time
the obscuring of the light of the moon by the intervention of the earth between it and the sun, a lunar eclipse, or the obscuring of the light of the sun by the intervention of the moon between it and a point on the earth, a solar eclipse
the movement or path of the earth or a heavenly body turning on its axis
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)