1
: a unit of length in astronomy equal to the distance that light travels in one year in a vacuum or about 5.88 trillion miles (9.46 trillion kilometers)
2
: an extremely large measure of comparison (as of distance, time, or quality)
seems like light-years ago
has light-years more talent
two minutes and yet light-years away from the crowded village—
Suzanne Patterson
Suzanne PattersonExamples of light-year in a Sentence
my sister and I are close in age, but personality-wise, there are light-years between us
Recent Examples on the Web
Just as astronomers use telescopes to examine celestial objects light-years away, novelists can invoke imagined civilizations to reveal truths closer to home, in part by forcing their characters into contact with alien environments and worldviews.
—Alexandra Oliva, The Atlantic, 12 June 2026
Then, in September 2015, twin LIGO observatories (one in Louisiana and one in Washington) picked up a signal lasting a fraction of a second—the death spiral of two black holes a billion light-years away.
—Nathaniel Janowitz, Wired News, 12 June 2026
This work was done using Hubble's Wide Field Camera 3, which can see tens of millions of light-years into the universe while still managing to capture incredible details of objects like M88.
—Chelsea Gohd, Space.com, 10 June 2026
This dazzling celestial object, dubbed the Crystal Ball Nebula, lies about 1,500 light-years from Earth in the Taurus constellation.
—Daniel Wine, CNN Money, 9 June 2026
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Alexandra Oliva, The Atlantic, 12 June 2026
Then, in September 2015, twin LIGO observatories (one in Louisiana and one in Washington) picked up a signal lasting a fraction of a second—the death spiral of two black holes a billion light-years away.
—Nathaniel Janowitz, Wired News, 12 June 2026
This work was done using Hubble's Wide Field Camera 3, which can see tens of millions of light-years into the universe while still managing to capture incredible details of objects like M88.
—Chelsea Gohd, Space.com, 10 June 2026
This dazzling celestial object, dubbed the Crystal Ball Nebula, lies about 1,500 light-years from Earth in the Taurus constellation.
—Daniel Wine, CNN Money, 9 June 2026
See All Example Sentences for light-year
Cite this Entry
“Light-year.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/light-year. Accessed 15 Jun. 2026.
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