- Astronomy. the time interval between two successive transits by the sun of the meridian directly opposite that of the observer; the 24-hour interval from one midnight to the following midnight.
- Law. the period of time from sunrise to sunset.
Origin of solar day
First recorded in 1755–65
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the period of time during which the earth makes one complete revolution on its axis relative to the sunSee day (def. 6)
- See under solar time.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.