The term retrograde is from the Latin word retrogradus – "backward-step", the affix retro- meaning "backwards" and gradus meaning "step". Its literal meaning is to go back to its original state, which is normally complex and less pleasant. Retrograde is most commonly an adjective used to describe the path of a planet as it travels through the sky, with respect to the zodiac, stars, and other bodies of the celestial canopy.
The celestial bodies of solar system can be studied in four groups. Firstly Sun and the Moon are not truly planets, hence are never retrograde. Secondly Rahu-Ketu are basically strategical points on ecliptic and always move in opposite (retrograde) motion. Thirdly, five planets- Mercury, Venus, Mars, Jupiter and Saturn, (in addition to our Earth) that we study in Vedic astrology. And fourthly trans-saturine planets (Uranus, Neptune and Pluto), which are icy-giant planets which are not considered in Vedic astrology primarily due to their distance from the Earth and the Sun and their nature & composition. However in Western astrology, they are also considered. These eight planets do get retrograde from time to time during their movement in the orbit around the Sun.
All planets during retrogression are at their closest position from Earth. Therefore if they could be seen, they appear larger and brighter. Their electromagnetic waves, reflected light, energy and vibrations are received in a more pronounced way than from a direct planet. Thus they are capable to influence natives and events in a more effective way.
Retrograde means Vakri in Sanskrit i.e twisted or crooked; it also means indirect, evasive, ambiguous, unknown, secret or having more than one meaning. A Vakri planet is also known as the Cheshta Bali graha. Vakragati confers exceptional i.e. Cheshtabala, to Vakri planet whose strong influence is expressed by the manner they affect the Natal Chart and by their transits.
When a planet is retrograde, its energies instead of flowing outwards, turns inward and the native becomes more subjective. The energy is slower manifesting in the external world, partly because the retrograde planets tend to break the time barrier. The individual brings memories of prior lifetimes into the present incarnation and does more of introspection.
A retrograde planet indicates intensity of a specific aspect of its significations, but some delay, problems and despair is also associated with it. It indicates a situation where the native is simple, without experience and knowledge, but not lacking in motivation.
FEW EXCERPTS FROM THE BOOK Retrograde Planets by Lt Col Raj Kumar:
"A native can modify the effects of a retrograde planet into positive or negative way by his action, will-power and thoughtprocess."
"In a positive frame, a retrograde planet is capable to present the life and various events in it into a new more flexible, changeable form. The word "Cheshta" in Cheshtabal means effort, action or exercise. Therefore a retrograde planet would have to put extra effort/ action in order to achieve his goal."
"Any planet when it gets retrograde, some of its intrinsic significations pertaining to its lordship of bhavas or the bhav where it is situated do suffer. There may be some shortcoming, delay, loss, distortion or partial breakdown, particularly in living aspects of theirs. If a planet is retrograde in the birth chart, whenever the planet during transit gets retrograde it would remind the native the need to attend to situations which started/ are caused to past lives actions."