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
Brecher's image captured spectacular detail in the sweeping spiral arms of the 260,000 light-year-wide galaxy gleaming with the intense light of star formation.
—Anthony Wood, Space.com, 28 Sep. 2025
In a surprising discovery, astronomers have found an enormous, shell-like structure called a nova super-remnant (NSR) in the Large Magellanic Cloud (LMC), a galaxy located approximately 160,000 light-years from Earth.
—Rupendra Brahambhatt, Interesting Engineering, 27 Sep. 2025
In our present-day Universe, that corresponds to a distance that’s approximately 18 billion light-years away.
—Ethan Siegel, Big Think, 25 Sep. 2025
The team suspects the host galaxy is a few billion light-years away, but research to determine the exact galaxy and distance is ongoing.
—Ashley Strickland, CNN Money, 22 Sep. 2025
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Anthony Wood, Space.com, 28 Sep. 2025
In a surprising discovery, astronomers have found an enormous, shell-like structure called a nova super-remnant (NSR) in the Large Magellanic Cloud (LMC), a galaxy located approximately 160,000 light-years from Earth.
—Rupendra Brahambhatt, Interesting Engineering, 27 Sep. 2025
In our present-day Universe, that corresponds to a distance that’s approximately 18 billion light-years away.
—Ethan Siegel, Big Think, 25 Sep. 2025
The team suspects the host galaxy is a few billion light-years away, but research to determine the exact galaxy and distance is ongoing.
—Ashley Strickland, CNN Money, 22 Sep. 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 3 Oct. 2025.
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