Astronomical unit

a unit of length, equal to the mean distance of the earth from the sun: approximately 93 million miles (150 million km).
abbreviation: au.
historical examples

that was one astronomical unit, equal to about ninety-three million miles, the distance from earth to the sun.
rip foster in ride the gray planet harold leland goodwin

in naming these enormous distances what astronomical unit is used?
the chautauquan, vol. iii, february 1883 the chautauquan literary and scientific circle

we are, so to speak, an astronomical unit, and we affect each other for better or for worse.
the moon destroyers monroe k. ruch

noun
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
(ās’trə-nŏm’ĭ-kəl)
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, p-rs-c.

the mean distance between the earth and the sun, about 98 million miles or 150 million kilometers. it is often abbreviated as au.