Definition of "mean solar day" [mean solar day]

• The period of time between two successive transits of the mean sun; the standard for the 24-hour day measured from midnight to midnight. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.