light
year
Plural
light-years
1
the distance that light travels in a year (about 9.46 trillion kilometers)
- Proxima Centauri, the closest star to Earth, is 4.24 light-years away.
- The galaxy is roughly 100,000 light-years in diameter.
- "That nebula is 1,500 light-years distant," explained the astronomer.
- A light-year is a unit of distance, not time—despite its name.
- The telescope captured light from a quasar billions of light-years away.
Synonyms: