terminator

American  

[tur-muh-ney-ter] / ˈtɜr məˌneɪ tər /

noun

1. a person or thing that terminates.

2. Astronomy. the dividing line between the illuminated and the unilluminated part of a satellite or planet, especially the moon.

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Etymology

Origin of terminator

1760–70; < Late Latin terminātor, equivalent to terminā ( re ) to terminate + -tor -tor

Example Sentences

Analyzing the planet's terminators, or the moving line separating the daylight and nocturnal sides of a given world, the scientists realized that there was tremendous asymmetry.

From Salon

One of the most disturbing observations for astronomers is the asymmetry between the planet's two terminators.

From Science Daily

The first thing to draw in is the terminator line.

From National Geographic Kids

Astronomers call the line between day and night the terminator, and when the moon is new and a thin crescent, that line marks the location of sunrise across the moon’s face.

From Scientific American

This drastic change is what the team dubbed solar cycle termination events, or terminators.

From Scientific American