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
Only 25 light-years from Earth, the star is young — about 440 million years old — and a proxy for what our solar system looked like in its formative years.
—Prabhat Ranjan Mishra, Interesting Engineering, 20 Dec. 2025
Imagine a distant light source, like a quasar, that sends light traveling for billions of light-years.
—Paul Sutter, Space.com, 20 Dec. 2025
In her fifth collaboration with filmmaker Yorgos Lanthimos, Emma Stone is light-years away from their childlike Poor Things creation.
—Eric Andersson, PEOPLE, 20 Dec. 2025
In 2008, astronomers detected an unexplained bright object located 25 light-years from Earth in the Piscis Austrinus constellation.
—Andrew Paul, Popular Science, 18 Dec. 2025
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Prabhat Ranjan Mishra, Interesting Engineering, 20 Dec. 2025
Imagine a distant light source, like a quasar, that sends light traveling for billions of light-years.
—Paul Sutter, Space.com, 20 Dec. 2025
In her fifth collaboration with filmmaker Yorgos Lanthimos, Emma Stone is light-years away from their childlike Poor Things creation.
—Eric Andersson, PEOPLE, 20 Dec. 2025
In 2008, astronomers detected an unexplained bright object located 25 light-years from Earth in the Piscis Austrinus constellation.
—Andrew Paul, Popular Science, 18 Dec. 2025
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 24 Dec. 2025.
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