Definitions for "Lunar day"
Keywords:  tidal, moon, axis, meridian, transit
The time of the rotation of the Earth with respect to the Moon, or the interval between two successive upper transits of the Moon over the meridian of a place. The mean lunar day is approximately 24.84 solar hours in length, or 1.035 times as great as the mean solar day.
the period of time taken for the moon to make one full rotation on its axis (about 27.3 sidereal days)
(or tidal day). The interval between two successive upper transit s of the moon over a local meridian. The period of the mean lunar day, approximately 24.84 solar hours, is derived from the rotation of the earth on its axis relative to the movement of the moon about the earth.