terminator

/ˈtɜːrmɪneɪtər/
noun
  1. A person or thing that ends something, especially a machine or device designed to destroy or eliminate.
    • He was known as the terminator of failing projects, always called in to shut them down.
    • The new software acts as a terminator for unwanted pop-up ads.
    • The robot in the movie was a deadly terminator sent from the future.
  2. The line separating the illuminated and dark parts of a celestial body, such as the moon or a planet.
    • Astronomers study the terminator of Mars to understand its surface features.
    • Through a telescope, you can see the terminator where day meets night on the moon.
    • The terminator on Earth is visible from space as a curved line of twilight.
Antonyms