|a unit of distance used in astronomy equal to the mean distance between the earth and the sun. 1 astronomical unit is equivalent to 1.495 × 1011 metres or about 9.3 × 107 miles|
astronomical unit [%PREMIUM_LINK%] (ās'trə-nŏm'ĭ-kəl) Pronunciation Key |
A unit of length equal to the average distance from Earth to the Sun, approximately 149.6 million km (92.8 million mi). It is used especially to measure distances within the solar system. Compare light-year, parsec.