Meaning of the word "light year" in English

What does "light year" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

light year

US /ˈlaɪt ˌjɪr/
UK /ˈlaɪt ˌjɪər/
"light year" picture

Noun

1.

a unit of astronomical distance equivalent to the distance that light travels in one year, which is nearly 6 trillion miles (9.46 trillion kilometers)

Example:
The nearest star to Earth, Proxima Centauri, is about 4.2 light years away.
Astronomers use the light year to measure vast distances in space.
2.

a very long distance or a great amount of time (used figuratively to emphasize a large difference)

Example:
Their technology is light years ahead of ours.
The two candidates are light years apart on this issue.