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

As the line of darkness — called the terminator — recedes, features near the border stand out in bold relief; the shadows become stronger and details are more easily seen. —Joe Rao, Space.com, 27 Nov. 2025

On Mercury, the dividing line between day and night, the terminator, is more than just a twilight zone. —Kaif Shaikh, Interesting Engineering, 13 Nov. 2025

Rachel LaMont was an absolute puzzle terminator on Survivor 47, dominating the brain-teasers during the pre-merge stage of the game, and then winning the final hanging bat puzzle immunity contest on her way to becoming the Sole Survivor. —Dalton Ross, Entertainment Weekly, 7 Oct. 2025

The crescent moon is a spectacular object in binoculars, with the terminator — the dividing line between day and night on the moon ‚— where to look for shadows and craters. —Jamie Carter, Forbes.com, 14 Sep. 2025

Word History

First Known Use

1652, in the meaning defined at sense 2

Rhymes for terminator

• activator
• actuator
• agitator
• alligator
• allocator
• alternator
• animator
• annotator
• applicator
• arbitrator
• aspirator
• aviator