The distance over which light can travel in a year's time; -- used as a unit in expressing stellar distances. It is more than 63,000 times as great as the distance from the earth to the sun.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). light year. Retrieved September 22, 2026, from http://smartdefine.org/light_year/definitions/2027854 |
| Chicago | Webster's. 2011. "light year" http://smartdefine.org/light_year/definitions/2027854 (accessed September 22, 2026). |
| Harvard | Webster's 2011, light year, Smart Define, viewed 22 September, 2026, <http://smartdefine.org/light_year/definitions/2027854>. |
| MLA | Webster's. "light year" 27 May 2011. Web. 22 September 2026. <http://smartdefine.org/light_year/definitions/2027854> |