sidereal 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 in reference to any star or to the vernal equinox at the meridian, equal to 23 hours, 56 minutes, 4.09 seconds in units of mean solar time.

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

• noun astronomy one day of sidereal time; the time in which Earth rotates once around its axis, relative to the point of the vernal equinox (about 23 hours, 56 minutes, 4 seconds)
• noun astronomy rotational period of Earth; the time in which Earth rotates around its axis 360 degrees

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

• noun the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day