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

This photo was taken as the Artemis II crew flew over the terminator, the dividing line between light and darkness on the moon. —Mark Osborne, CBS News, 11 Apr. 2026

Glover also noted the stark view of the Moon’s terminator, the transition between day and night. —Stephen Clark, ArsTechnica, 9 Apr. 2026

Glover, for instance, was particularly captivated by the jagged topography along the moon’s terminator, the dividing line between its illuminated side and the side cloaked in darkness. —Denise Chow, NBC news, 7 Apr. 2026

In the priority 3 group are items like examining the moon's limb and terminator, appraising the celestial body's volcanic history, and making observations of Earth from deep space. —Leonard David, Space.com, 6 Apr. 2026

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