light-year

noun
\ˈlīt-ˌyir \

Definition of light-year 

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

Synonyms for light-year

Synonyms

galaxy, world

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First Known Use of light-year

1867, in the meaning defined at sense 1

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The first known use of light-year was in 1867

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More Definitions for light-year

light-year

noun

English Language Learners Definition of light-year

: a unit of distance equal to the distance that light travels in one year (about 5.88 trillion miles or 9.46 trillion kilometers)

light-years —used to say that someone or something is much better or more advanced than others

—used to refer to a time that is or seems very far away

light-year

noun
\ˈlīt-ˌyir\

Kids Definition of light-year

: a unit of length in astronomy equal to the distance that light travels in one year or about 5.88 trillion miles (9.46 trillion kilometers)

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