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
The protostars sit in a region known as FS Tau, located around 450 light-years away, which has become a popular target for astronomers aiming to study the evolution of low-mass stars.
—
Robert Lea,
Space.com,
3 July 2026
And like the photons that travel billions of light-years to reach us, new fragments are constantly falling into place.
—
Quanta Magazine,
2 July 2026
The luminous formation about 16 million light-years away visible around the galaxy is called a starburst ring, home to new stars.
—
Andrew Paul,
Popular Science,
2 July 2026
The Milky Way is our home galaxy with a disc of stars that spans more than 100,000 light-years.
—
Eric Lagatta,
USA Today,
2 July 2026
See All Example Sentences for light-year
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Robert Lea,
Space.com,
3 July 2026
And like the photons that travel billions of light-years to reach us, new fragments are constantly falling into place.
—
Quanta Magazine,
2 July 2026
The luminous formation about 16 million light-years away visible around the galaxy is called a starburst ring, home to new stars.
—
Andrew Paul,
Popular Science,
2 July 2026
The Milky Way is our home galaxy with a disc of stars that spans more than 100,000 light-years.
—
Eric Lagatta,
USA Today,
2 July 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 5 Jul. 2026.
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