retrograde

动词 retrograde:

1. move backward in an orbit, of celestial bodies
2. move in a direction contrary to the usual one
3. move back
   同义词：retreat
4. go back over
   同义词：rehash, hash over
5. get worse or fall back to a previous condition
   同义词：regress, retrogress

形容词 retrograde:

1. moving from east to west on the celestial sphere; or--for planets--around the sun in a direction opposite to that of the Earth
2. of amnesia; affecting time immediately preceding trauma
3. going from better to worse
   同义词：retrogressive
4. moving or directed or tending in a backward direction or contrary to a previous direction
   同义词：retral

ret.ro.grade

adj.（形容词）
Moving or tending backward.
后退的：向后移动的或向后倾的
Opposite to the usual order; inverted or reversed.
颠倒的：与通常顺序相对的；倒转的或颠倒的
Reverting to an earlier or inferior condition.
退化的：回到较早或较低级的状态的
Astronomy
【天文学】
Of or relating to the orbital revolution or axial rotation of a planetary or other celestial body that moves clockwise from east to west, in the direction opposite to most celestial bodies.
逆行的：行星或其它天体沿轨道旋转或绕轴旋转的，该天体顺着与大多数天体相反的方向由东向西顺时针运动
Of or relating to the brief, regularly occurring, apparently backward movement of a planetary body in its orbit as viewed against the fixed stars, caused by the differing orbital velocities of Earth and the body observed.
后退的：行星所做的短暂有规律的运动的，以静止星体为参照物进行观察时，这种运动显然是后退的，这是由地球和所观察天体具有不同的轨道速度引起的
Archaic Opposed; contrary.
【古语】 对立的：相对的；相反的
v.intr.（不及物动词）
ret.ro.grad.ed,ret.ro.grad.ing,ret.ro.grades
To move or seem to move backward.See Synonyms at recede
后退，逆行：向后移动或似乎向后移动参见 recede
To decline to an inferior state; degenerate.
退步：降至较低级的状态；退化

来源：
Middle English
中古英语
from Latin retrôgradus
源自 拉丁语 retrôgradus
from retrôgrado [to go back]
源自 retrôgrado [回去]
retrô- [retro-]
retrô- [表.后退的.]
-gradus [walking] from grado [to go] * see ghredh-
-gradus [步行] 源自 grado [去] *参见 ghredh-

【引伸】
ret.rograda.tion
ret.rograde.ly
adv.（副词）