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
About the size of Saturn, the new world is circling a red dwarf star about 111 light-years away.
—Alex Knapp, Forbes.com, 27 June 2025
Also known as Andromeda, the Milky Way’s most immediate neighbor is about 2.5 million light-years away, and provides an excellent option for studying how spiral galaxies form and evolve over time.
—Andrew Paul, Popular Science, 26 June 2025
Once detected, neutrinos can reveal impressive information about the nature of cosmic events that took place light-years away, as Stephanie Wissel, an astrophysicist at the Pennsylvania State University, says in a statement.
—Amber X. Chen, Smithsonian Magazine, 26 June 2025
The star-forming regions that resemble clouds composed of dust and gas are located thousands of light-years away from Earth in the constellation Sagittarius.
—Eric Lagatta, USA Today, 25 June 2025
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Alex Knapp, Forbes.com, 27 June 2025
Also known as Andromeda, the Milky Way’s most immediate neighbor is about 2.5 million light-years away, and provides an excellent option for studying how spiral galaxies form and evolve over time.
—Andrew Paul, Popular Science, 26 June 2025
Once detected, neutrinos can reveal impressive information about the nature of cosmic events that took place light-years away, as Stephanie Wissel, an astrophysicist at the Pennsylvania State University, says in a statement.
—Amber X. Chen, Smithsonian Magazine, 26 June 2025
The star-forming regions that resemble clouds composed of dust and gas are located thousands of light-years away from Earth in the constellation Sagittarius.
—Eric Lagatta, USA Today, 25 June 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 30 Jun. 2025.
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