Merriam-Webster Collegiate Dictionary - retrograde

 I. adjective  Etymology: Middle English, from Latin retrogradus, from retrogradi  Date: 14th century  1.  a.  (1) having or being motion in a direction contrary to that of the general motion of similar bodies and especially east to west among the stars Saturn is ~ for another week the ~ motion of Mercury  (2) having or being a direction of rotation or revolution that is clockwise as viewed from the north pole of the sky or a planet a ~ orbit  b.  (1) moving, occurring, or performed in a backward direction a ~ step  (2) occurring or performed in a direction opposite to the normal or forward direction of conduction or flow ~ ejaculation — compare anterograde 1  c. contrary to the normal order ; inverse  2. tending toward or resulting in a worse or previous state  3. archaic contradictory, opposed  4. characterized by retrogression  5. affecting memories of a period prior to a shock or seizure ~ amnesia  6. retro ~ fashion  • ~ly adverb  II. adverb  Date: circa 1619 backward, reversely  III. verb  Etymology: Latin retrogradi, from retro- + gradi to go — more at grade  Date: 1582  transitive verb archaic to turn back ; reverse  intransitive verb  1.  a. to go back ; retreat  b. to go back over or recapitulate something  2. to decline to a worse condition