Retrograde generally means moving backward or in a direction opposite to the normal or usual direction. In astronomy, retrograde motion refers to the apparent or actual motion of a planet or other celestial body moving in the opposite direction to the rotation of its primary (such as a star or planet it orbits). For example, most planets in our Solar System orbit the Sun counterclockwise (prograde motion), but sometimes a planet appears to move backward through the zodiac from the perspective of Earth, which is called apparent retrograde motion. This is an optical illusion caused by the relative positions and motions of Earth and the planet in their orbits. More broadly, the term retrograde can also describe anything moving backwards, occurring in a reverse direction, or going from a better to a worse state. In astrology, a planet is said to be retrograde when it appears to move backward in the zodiac, and this is believed to be a time for reflection, reevaluation, or delays in matters related to that planet. So, retrograde means moving backward or contrary to the usual direction—whether literally in space or figuratively in other contexts. This explanation covers the scientific, linguistic, and astrological meanings of retrograde. If you want a specific type of retrograde explained (like Mercury retrograde or retrograde in another context), please let me know.