The Collaborative International Dictionary of English v.0.48:

Retrograde \Re"tro*grade\, a. [L. retrogradus, from retrogradi,
   retrogressus, to retrograde; retro back + gradi to step: cf.
   F. r['e]trograde. See Grade.]
   1. (Astron.) Apparently moving backward, and contrary to the
      succession of the signs, that is, from east to west, as a
      planet. --Hutton.
      [1913 Webster]

            And if he be in the west side in that condition,
            then is he retrograde.                --Chaucer.
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   2. Tending or moving backward; having a backward course;
      contrary; as, a retrograde motion; -- opposed to
      progressive. "Progressive and not retrograde." --Bacon.
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            It is most retrograde to our desire.  --Shak.
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   3. Declining from a better to a worse state; as, a retrograde
      people; retrograde ideas, morals, etc. --Bacon.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Retrograde \Re"tro*grade\, v. i. [imp. & p. p. Retrograded; p.
   pr. & vb. n. Retrograding.] [L. retrogradare, retrogradi:
   cf. F. r['e]trograder.]
   1. To go in a retrograde direction; to move, or appear to
      move, backward, as a planet.
      [1913 Webster]

   2. Hence, to decline from a better to a worse condition, as
      in morals or intelligence.
      [1913 Webster]

WordNet (r) 3.0 (2006):

retrograde
    adj 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 [ant: direct]
    2: of amnesia; affecting time immediately preceding trauma [ant:
       anterograde]
    3: going from better to worse [syn: retrograde,
       retrogressive]
    4: moving or directed or tending in a backward direction or
       contrary to a previous direction [syn: retral,
       retrograde]
    v 1: move backward in an orbit, of celestial bodies
    2: move in a direction contrary to the usual one; "retrograding
       planets"
    3: move back; "The glacier retrogrades" [syn: retrograde,
       retreat]
    4: go back over; "retrograde arguments" [syn: retrograde,
       rehash, hash over]
    5: get worse or fall back to a previous condition [syn:
       regress, retrograde, retrogress] [ant: advance, come
       along, come on, get along, get on, progress, shape
       up]