light-year
noun
the distance traversed by light in one mean solar year, about 5.88 trillion mi. (9.46 trillion km): used as a unit in measuring stellar distances. lt-yr
light-years
-
pluralof light-year.plural
The grammatical form denoting more than one person, place, thing, or idea.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
If a galaxy is 11 billion light-years away, its light has traveled for 11 billion years before reaching Earth.
From Science Daily ● Sep. 17, 2026
“They have to be light-years ahead of everyone else to gain ground,” he said.
From The Wall Street Journal ● Sep. 13, 2026
The measurements allowed the team to trace hydrogen across distances of several million light-years, roughly comparable to the separation between the Milky Way and the neighboring Andromeda galaxy.
From Science Daily ● Sep. 9, 2026
So scientists anchor the world’s coordinates to far-off stillness: quasars, the luminous cores of galaxies billions of light-years away, observed nightly by radio telescopes across multiple continents and cross-checked with lasers bounced off satellites.
From The Wall Street Journal ● Aug. 7, 2026
According to Rees, the number of light-years to the edge of this larger, unseen universe would be written not "with ten zeroes, not even with a hundred, but with millions."
From "A Short History of Nearly Everything" by Bill Bryson
