solar day

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The time required for a single rotation of the earth on its axis with respect to the sun, varying slightly throughout the year due to variations in the earth's orbit and other factors.
• noun A mean solar day.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun astronomy one day of solar time, the time between successive noons; the time in which a planet such as Earth apparently rotates once around its axis, relative to the sun (on Earth about 24 hours as an average - the length of solar day is not constant throughout the year)

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun time for Earth to make a complete rotation on its axis