light-year

light-year also light year (ltyîr)

n.

1. The distance that light travels in a vacuum in one year, approximately 9.46 trillion (9.46 × 10¹²) kilometers or 5.88 trillion (5.88 × 10¹²) miles.

2. Informal A long way. Often used in the plural: a small town light-years away from the action of the capital.

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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 unitparsec

Thesaurus

Noun

1.

light-year - the distance that light travels in a vacuum in 1 year; 5.88 trillion miles or 9.46 trillion kilometers light year astronomy unit - a linear unit used for astronomical distances light hour - the distance light travels in a vacuum in one hour; approximately one billion kilometers light minute - the distance light travels in a vacuum in one minute; approximately 18 million kilometers light second - the distance light travels in a vacuum in one second; approximately 300,000 kilometers