light-year

[lahyt-yeer, -yeer]

Phonetic (Standard)IPA

noun

Astronomy.��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,
1. a very great distance, especially in development or progress.
  The new computer is light-years ahead of the old one.
2. a very long time.
  It's been light-years since I've seen my childhood friends.

light year

noun

a unit of distance used in astronomy, equal to the distance travelled by light in one year, i.e. 9.4607��×��10 ¹² kilometres or 0.3066 parsecs

light-year

The distance that light travels in a vacuum in one year, equal to about 9.46 trillion km (5.88 trillion mi). Light-years are used in measuring interstellar and intergalactic distances.
Compare astronomical unit parsec

light year

The distance traveled by light in a year (over five trillion miles); a unit for measuring distances outside the solar system. The star nearest to our sun, Alpha Centauri, is more than four light years away.

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Word History and Origins

Origin of light year¹

First recorded in 1885–90

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Example Sentences

Examples have not been reviewed.

That’s silly for any number of reasons, not least the fact the campaign is political light-years away.

From

One was his debut, “Boxcar Sessions,” an incredibly left-of-center release that was still definitely rooted in hip-hop, though it still sounded light-years ahead of its time.

From

The exact intensity of Tsuchinshan-ATLAS’s brightness is tough to predict; the comet is still light-years away from Earth, after all.

From

Instead of orbiting our Sun, this exoplanet revolves around a star in the Virgo constellation roughly 200 light-years from Earth.

From

He also suggested that while poultry farmers have really upped their biosecurity in the past several years, the dairy industry is “light-years” behind when it comes to creating physical barriers.

From

lightwood lign-

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