sidereal year

noun

Definition of sidereal year 

: the time in which the earth completes one revolution in its orbit around the sun measured with respect to the fixed stars : 365 days, 6 hours, 9 minutes, and 9.5 seconds of mean time

First Known Use of sidereal year

1765, in the meaning defined above

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The first known use of sidereal year was in 1765

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