(Informal) A long way:
A unit of astronomical length equal to 3.26 light-years. It is based on the distance from Earth at which a star would have a parallax of one second of arc. Its metric equivalent is about 30.8 trillion km (19.1 trillion mi). It is used in measuring distances in interstellar and intergalactic space. The closest star to Earth, Alpha Centauri, is about 1.3 parsecs away.
Abbreviation of astronomical unit
Find another word for astronomical-unit. In this page you can discover 3 synonyms, antonyms, idiomatic expressions, and related words for astronomical-unit, like: light year, parsec and au.