terminator
noun
ter·mi·na·tor
ˈtər-mə-ˌnā-tər 
1
: the dividing line between the illuminated and the unilluminated part of the moon's or a planet's disk
2
: one that terminates
Examples of terminator in a Sentence
Recent Examples on the Web
However, in some cases, lightning strikes happened mostly on the nightside, just past the day-night terminator line.
—
Paul Sutter, Space.com, 20 May 2025
The image features Mercury’s terminator—the separation between day and night—at the center, nearly parallel to the Prokofiev, Kandinsky, Tolkien and Gordimer craters.
—Margherita Bassi, Smithsonian Magazine, 13 Jan. 2025
The 57-mile-wide (93 km) Copernicus Crater will also be easily visible on the nights surrounding May 20 a little left of the terminator, close to the lunar equator.
—Anthony Wood, Space.com, 19 May 2025
The area at the left of the craters and terminator is the Borealis Planitia, Mercury’s largest expanse of smooth volcanic plains, which was formed by large volcanic eruptions 3.7 billion years ago.
—Margherita Bassi, Smithsonian Magazine, 13 Jan. 2025
See All Example Sentences for terminator
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Paul Sutter, Space.com, 20 May 2025
The image features Mercury’s terminator—the separation between day and night—at the center, nearly parallel to the Prokofiev, Kandinsky, Tolkien and Gordimer craters.
—Margherita Bassi, Smithsonian Magazine, 13 Jan. 2025
The 57-mile-wide (93 km) Copernicus Crater will also be easily visible on the nights surrounding May 20 a little left of the terminator, close to the lunar equator.
—Anthony Wood, Space.com, 19 May 2025
The area at the left of the craters and terminator is the Borealis Planitia, Mercury’s largest expanse of smooth volcanic plains, which was formed by large volcanic eruptions 3.7 billion years ago.
—Margherita Bassi, Smithsonian Magazine, 13 Jan. 2025
See All Example Sentences for terminator
Cite this Entry
“Terminator.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/terminator. Accessed 7 Jun. 2025.
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