Etymology, from wikipedia:
The term retrograde is from the Latin word retrogradus – “backward-step”, the affix retro- meaning “backwards” and gradito step or “to go”. Retrograde is most commonly an adjective used to describe the path of a planet as it travels through the night sky, with respect to the zodiac, stars, and other bodies of the celestial canopy. In this context, the term refers to planets, as they appear from Earth, to stop briefly and reverse direction at certain times though in reality, of course, we now understand that they perpetually orbit in the same uniform direction.
In general, retrograde periods of planets signify periods of time when we naturally turn inward, to review and absorb more deeply the meaning of a transit that normally occurs only once per cycle. Retrograde periods include two extra transits of the same planet over the same point. So we get a chance to “get it right,” by revisiting the same situation (on the second pass) and then (during the third pass) working with it in a new and more enlightened manner. At least that’s the theory! In other words, planetary retrograde periods help us catch up with ourselves by revisiting places within ourselves that we glossed over, perhaps too lightly, the first time around. For Venus, those “places” have to do with values, money, relationships, what we like and dislike. For Mercury, those “places” have to do with the mind, ideas, communication and transportation. Retrograde periods are especially meaningful when they conjunct natal planets, thus deepening our response to the situation represented by the conjunction.
On this very day of the Chinese New Year of the Yang Horse, Venus stations to go into direct motion. Venus retrograde periods are somewhat rare: 30-43 days every 18 months. Current Venus retrograde period: December 21 – January 31, 2014:
Mercury retrograde periods are more common. Mercury goes retrograde for three weeks, three times a year. Current Mercury retrograde period: February 6 – 28, 2014.