light-year
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>
First Known Use of LIGHT-YEAR
1888
Related to LIGHT-YEAR
- Synonyms
- light-year, world
light-year
noun (Concise Encyclopedia)Distance traveled by light moving in a vacuum in one year, at its accepted speed of 186,282 mi/second (299,792 km/second). It equals about 5.9 trillion mi (9.5 trillion km), 63,240 astronomical units, or 0.307 parsec.
Learn More About LIGHT-YEAR
Browse
Next Word in the Dictionary: light yellowwood
Previous Word in the Dictionary: lightwood
All Words Near: light-year
Previous Word in the Dictionary: lightwood
All Words Near: light-year
Seen & Heard 
What made you want to look up light-year? Please tell us where you read or heard it (including the quote, if possible).


See 








